Laboratory Manual - Non Automatic Weighing Devices...Weighing devices and major components are...

Laboratory Manual Non Automatic Weighing Devices Page: 1 of 15

Part: 1 Section: 1 Introduction, guidelines and application of limits of error

1.0 Purpose of this manual The purpose of this manual is: � to provide detailed criteria enabling manufacturers of weighing devices, technologists of the

Measurement Canada Approval Services Laboratories and metrologists of United States National Type Evaluation Laboratories to determine whether the design, operation and characteristics of the devices they build or evaluate meet the requirements or the intent of the requirements prescribed by the Specifications for Non Automatic Weighing Devices; and

� to describe the laboratory evaluation and test procedures for non automatic weighing devices so as to

ensure that they are applied uniformly. Warning: from time to time the criteria provided in this manual may have to be updated due to

weighing device technology changes. It is recommended that manufacturers contact the manager of the Approval Services Laboratories to discuss any new and special features that they plan to incorporate into their devices to ensure that they comply with the requirements.

2.0 Scope This manual provides the examination criteria and test procedures for non automatic weighing devices and major components thereof that may be subject to separate evaluation. A non automatic weighing device is a weighing device that requires the intervention of an operator in the weighing process. Such devices weigh commodities statically and require the intervention of the operator during the weighing process, for example to apply or remove the material to be weighed from the load receiving element, to read the weight or initiate the printing of tickets, etc. Examples of non-automatic weighing devices are:

• retail computing scales used in grocery stores to weigh food in the presence of consumers; • railway track scales used for the static single-draft weighing of railway cars; • vehicle-mounted scales used to weigh statically anhydrous ammonia (NH3).

An automatic weighing device weighs without the intervention of an operator and follows a predetermined program of automatic processes that are characteristic of the device. Weighing can be done in motion or statically. Examples of automatic weighing devices are:

• continuous totalizing weighing devices (commonly called conveyor belt scales); • discontinuous totalizing weighing devices (automatic bulk weighers); • self-indicating railway track scales (commonly called in-motion railway scales); • check-weighing machines; • weight grading machines; • automatic weight fillers.



Note: An automatic weighing device designed for the static weighing of prepackaged commodities of

variable weight to which accessories are attached to automate the application and removal of packages remains in the non automatic category although the system is somewhat automated.

3.0 Abbreviations used in this manual AC Alternating Current AZSM Automatic Zero-Setting Mechanism AZT or AZTM Automatic Zero Tracking Mechanism Max Maximum Device Capacity CDN Canadian CofZ Centre of Zero d Scale Interval (also: division, graduation) DC Direct Current DUT Device Under Test e Verification Scale Interval IZSM Initial Zero-Setting Mechanism LCD Liquid Crystal Display LED Light Emitting Diode LRE Load Receiving/Weighing Element MC Measurement Canada Emin Minimum Permissible Error Emax Maximum Permissible Error n Number of Intervals (graduations, divisions) OIML International Organization of Legal Metrology POS Point-of-Sale System RH Relative Humidity SAZSM Semi Automatic Zero-Setting Mechanism VDT Video Display Terminal ZU Zone of Uncertainty +ve Positive -ve Negative Technologist means a member of the staff of the Measurement Canada Approval Services Laboratory who is responsible for evaluating devices. Laboratory means the Approval Services Laboratories. 4.0 Review and up-date of the requirements, communication and confidentiality Evaluation for approval usually consists of three parts: (1) examination of the design of the device; (2) performance testing, including susceptibility to influence factors; and (3) durability testing. Examination of the design is intended to ensure that the device conforms to prescribed standards, is appropriate to the intended use and has the characteristics that will ensure accurate measurement and reasonable protection from fraud. Such examination is particularly important when a device has new or unusual characteristics or features. The technologist has to determine whether these new characteristics meet the requirements. Any major question will be reviewed by the Program Development Directorate and Engineering and Laboratory Services. This manual will be updated from time to time to take into account of technological changes. Good communications internally and with clients are essential to the effectiveness of the device approval program. All information relating to the design, performance and intended use of devices submitted for approval is confidential. The Laboratory is bound to protect this information and must limit access to it, or to data developed during the approval process, to properly authorized organizations or individuals (usually the applicant or manufacturer).



The technologist is not necessarily an expert in the design of weighing devices. When a noncompliance comes to light, the technologist is not required to determine the cause or suggest ways of correcting it. The technologist informs the applicant, who is responsible for solving the problem. 5.0 Weighing devices and major components subject to approval evaluation Weighing devices and major components are normally examined and tested entirely in the Laboratory. However, some devices and load receiving/weighing elements, because of their size or capacity and the present limitations of the Laboratory, are evaluated and tested partly or entirely in the field. In addition, some peripheral devices that perform simple complementary metrological functions such as price computation or that cannot affect the performance of the device to which they are interfaced are evaluated and tested in the field only. Such is the case of a printer that merely reproduces the weight values displayed by the device. The table below gives an overview of which device types are evaluated in the laboratory and which are evaluated in the field. Table 1: Test locations for various device types

Device Type Test Location

Any electronic or mechanical primary indicating element that performs metrological functions.

Examined and tested entirely in the Laboratory.

Secondary indicating element, printer, secondary display, price-computing scale, cash register and any other peripheral equipment that may be interfaced to a device but does not alter the device performance or does not perform metrological functions.

These elements are evaluated in the field by inspectors on initial inspection of the weighing device. Such elements will, however, be examined and tested by the Laboratory if they are built into a device submitted for approval.

Cash register/software of a point-of-sale system (POS) that performs significant metrological functions that may affect measurement (functions other than the computation of total prices on the basis of the weight data provided by the weighing element or the scale, and the printing of the data on a cash register tape.

Examined and tested entirely in the Laboratory. Weighing elements intended to be interfaced with cash registers of that category may be approved separately.

Complete weighing device and load receiving/weighing element whose capacity is not more than 1000 kg or whose dimensions do not exceed 1.6 m x 1.6 m.

Examined and tested entirely in the Laboratory, including temperature susceptibility tests and durability tests.

Complete weighing device and load receiving/weighing element whose capacity is more than 1000 kg to no more than 10,000 kg and whose dimensions do not exceed 1.6 x 1.6 m.

Examined and tested entirely in the Laboratory. Only partial tests are performed in the environment chamber.

Complete weighing device and load receiving/weighing element whose capacity is more than 10,000 kg or whose dimensions exceed 1.6 m x 1.6 m. (This category includes vehicle scales, tank scales, large capacity hopper scales and railway track scales.)

The examination and testing are conducted in the field in accordance with the requirements of the Weights and Measures document entitled “Class Approval”. Note that indicating elements for these types of devices are examined and tested in the Laboratory.

Software that performs significant metrological functions. Examined and tested entirely in the Laboratory. Policy, requirements and procedures concerning the evaluation of software is being drafted.



6.0 Request for approval and assistance to be provided during evaluation The applicant must complete the appropriate approval request form and send it to the manager of the Approval Services Laboratories. The applicant must also provide two copies of the instruction manual and the operator’s manual, photographs of the device, and blueprints or drawings showing the arrangement of the components of the device. The applicant must provide the Laboratory technologist with all pertinent details concerning the construction, operating and sealing characteristics of the device, the various functions that the device can perform, the intended use of the device, and its installation particulars. At the technologist’s request, the applicant must submit one or more sample devices and one or more pieces of peripheral equipment, such as a printer, that will be of assistance in assessing the operation of the device in association with such equipment. In some cases, the applicant will be asked to supply and assemble the material and equipment necessary to conduct the adequate tests (for example: supports for overhead-rail scales). The applicant must provide all assistance necessary to enable the technologist to properly conduct the evaluation of the device. The applicant must prepare, set the operating parameters of, calibrate and install, as applicable, the sample devices necessary to allow proper assessment. The purpose of these measures is to make for more efficient assessment of devices. 7.0 Selection criteria for sample devices Criteria have been established to determine the number of devices and the particular devices of the same type or family that are required to be submitted to the Laboratory for type evaluations. Deviations from the criteria occur when the criteria do not target those devices within the family that may represent the most difficult technological challenge to achieve compliance with the requirements. The general criteria are as follows:

• The devices with the largest and the smallest capacity in the family. • The devices with the largest number of graduations. • The devices with the smallest interval values. • The devices whose load receiving element has the largest surface area for a given capacity. • The various types of load cell or load cells made of different materials (options). • The device or major component with the fullest options. • The various power supplies available (DC, AC).

Furthermore, when the housing is available in various materials (plastic, stainless steel), each version must be submitted for radio interference testing (RFI). Each version of the housing must be examined for compliance with general requirements, especially sealing requirements. So-called “intrinsically safe” housings may also have to be submitted. The technologist, in consultation with the manufacturer, will determine how many and what devices of a family or type have to be submitted to the Laboratory for evaluation. Note: Large capacity devices such as vehicle scales are tested individually in the field after

installation in accordance with the Weights and Measures document entitled “Class Approval”. Indicating elements of such devices, however, must be of a design approved by the Approval Services Laboratories.

8.0 Representativeness of sample devices and peripheral equipment submitted for evaluation The sample device submitted for evaluation and approval testing must be complete in assembly and representative of the model that will be marketed.



If the device can be used with one or more peripheral modules, such as a printer, or if the device can be configured or adjusted remotely by means of a device such as a computer, the applicant must provide a representative peripheral module to allow assessment of the compatibility and operation of the device when connected to peripheral modules. A device or major component may be designed to perform functions that are not allowed in Canada but are authorized in other countries, for example, use of a unit of measurement prohibited in Canada but allowed in the United States. The device may have such functions provided that the prohibited features can be deactivated and sealed. A counting feature incorporated in weighing devices is not tested by the Laboratory. It may, however, remain active and be used in trade. Devices used to count numbers of units are not subject to the Weights and Measures Act. 9.0 Testing, marking and approval of complete devices and separate components Complete weighing devices consisting of an indicating element and a load receiving/weighing element in the same housing are tested as complete units and are approved as such. The major components of such devices cannot be separated and connected to other components to form a new device. A single identification plate giving all the prescribed information is required. Complete weighing devices made up of individual components or modules connected together are tested as complete units if the applicant specifies that the modules are not intended to be separated and connected to other modules approved separately to form another device. In this case, a single approval notice will be issued for the complete device. The Notice of Approval will state that the modules of the device cannot be separated and used with other modules to form a different device. A single identification plate for the entire device giving all the prescribed information will be required. If the applicant indicates that the major components of a device like that described in the foregoing paragraph may be used with other major components approved separately, the latter components will then be tested separately to a limit of error equal to 0.7 times the acceptance limit of error normally applied to a complete device. Each major component of the device will have to bear its own identification plate giving the prescribed information. A single Notice of Approval may be issued for the complete device stating that the major components of the device may be separated and connected to other compatible approved modules, or each major component may be approved separately. Major components submitted individually for approval are tested separately. In this case, a tolerance of 0.7 times the acceptance limit of error normally applied to a complete device will be used. These components will be approved separately and may be connected to other compatible approved devices. Each major component must be marked with the prescribed information. 10.0 Alteration, modification and adjustment during evaluation The applicant will be informed of the progress of the examination and testing during evaluation and will be notified promptly of any points of noncompliance. The applicant may then make the necessary corrections or adjustments. The technologist will ensure that any alterations or adjustments made have corrected the noncompliance. The technologist will also have to ensure that any alterations or adjustments made have not changed other characteristics already verified and tested. Where alterations or adjustments are made to a device during evaluation, the technologist will have to determine from the nature of the alteration or adjustment whether some or all of the tests have to be repeated.



11.0 Repeatability of tests during evaluation The Laboratory endeavors to design and execute the tests in a way and under conditions that ensure as much reproducibility of the results as possible. Some degree of variation, however, is unavoidable. Devices that clearly do not meet the performance requirements would not meet them even under more controlled conditions, no matter how many times the tests are repeated. A device whose performance is marginally unsatisfactory may be able to meet the limits of error once out of two or three times if the tests are repeated several times. The performance of such a device is nevertheless unsatisfactory. The Approval Services Laboratory is under no obligation to repeat any tests or portions of tests at the applicant’s request where such tests have been duly performed and any repetition of them would add nothing to the evaluation of the device. 12.0 Alterations subsequent to approval The manufacturer or the applicant must notify the Approval Services Laboratory of its intent to make alterations to the design of an approved device or major component. The alterations may be major or minor. They can include changing the appearance of the housing, changing the material of which the housing is made, physical reorganization of the electronic cards, modification of the software, additional features or options, and so on. Depending on the scope of the alterations and their potential impact on the performance of the device and its overall compliance with requirements, the Approval Services Laboratory may merely endorse the file and update the Notice of Approval if necessary, or it may carry out a re-examination and partial or complete retesting of the device. Where the Approval Services Laboratory deems necessary, it may ask the manufacturer to submit a device for examination. 13.0 Updating designs pursuant to changes in specifications When ministerial design, composition, and construction specifications are changed, the designs of devices approved prior to the change in the specifications do not have to be altered to meet the new requirements. They may continue to be marketed without alteration. Unless otherwise indicated, changes to performance requirements, such as the limits of error, apply to all designs of device even if they were approved prior to the introduction of the changes. 14.0 Limits of error 14.1 General The limits of error depend upon the class designation of the device and its value of verification scale interval "e" (most of the time e = d (graduation)). Contrary to the previous weights and measures requirements, the limits of error are the same for increasing and decreasing loads, and they are not increased by half-graduation for digital-display devices. 14.2 Limits of error applicable to complete devices and major components tested separately The full acceptance limits of error apply to complete devices subjected to approval testing.



When a major component, such as an electronic indicating element or a load receiving/weighing element, is tested separately, the limits of error that apply are 0.7 times the acceptance limits of error normally applied to a complete device. This does not apply to a major component that is the only element likely to produce measurement errors (linearity, hysteresis, repeatability and so on) because of disturbances or influence factors (for example, a load receiving/weighing element that produces a digital signal interpretable by computer software). In this case, the full acceptance limits of error will be granted to the load receiving/weighing element. 14.3 Limits of error applicable to multiple range and multi-interval devices A multiple range device has two or more weighing ranges with different capacities and different intervals for the same load receiving/weighing element, and each range extends from zero to its maximum capacity. Each range is considered a separate device. The limits of error for each range are determined on the basis of the value of the verification scale interval of that range. A multi-interval device has a single weighing range divided into partial weighing ranges with different intervals, and the weighing range is determined automatically by the load applied, for increasing and decreasing loads. The limits of error are determined on the basis of the class of the device and the value of the verification scale interval "e" of the partial range corresponding to the load applied. The following example shows how to determine the limits of error applicable to a Class III 15 kg weighing device with partial ranges and verification scale intervals "e" (graduations) set as follows: First range 0-2 kg x 1 gram Second range 2-5 kg x 2 grams Third range 5-15 kg x 5 grams Given that the limits of error are calculated as follows: Table 2: Acceptance limits of error applicable to Class III weighing devices

Load expressed innumber of verification scale

intervals "e"

Acceptance limits of error expressed innumber of verification scale intervals "e"

0 - 500 ±0.5 e > 500 - 2 000 ±1 e

> 2 000 - 4 000 ±1.5 e > 4 000 ±2.5 e

The limits of error applicable to each range are therefore: Table 3: Example of typical limits of error

Number of intervals "e" Value in kilograms Limits of error

(Acceptance)

First Range (e = 1 g)

0 - 500 e > 500 - 2 000 e

0 - 500 g > 500 g - 2 kg

0.5 g (0.5 e) 1 g (1 e)

Second Range (e = 2 g)

0 - 500 e > 500 - 1 000 e

> 1000 - 2 000 e > 2000 - 2 500 e

0 - 1 kg > 1 - 2 kg > 2 - 4 kg > 4 - 5 kg

N/A N/A

2 g (1 e) 3 g (1.5 e)

Third Range (e = 5 g)

0 - 500 e > 500 - 1 000 e

0 - 2.5 kg > 2.5 - 5 kg

N/A N/A



> 1000 - 2 000 e > 2000 - 3 000 e

> 3 000 e

> 5 - 10 kg > 10 - 15 kg

> 15 kg

5 g (1 e) 7.5 g (1.5 e)

N/A 15.0 Determining the error before rounding - digital-display devices In some cases during approval testing, the internal error or error before rounding will have to be determined in order to accurately establish the performance curve of the device and whether it meets the prescribed limits of error. When the device is tested to full capacity and the errors noted are well within the prescribed limits, direct reading of the registrations may be satisfactory. If the errors are marginal, it will be necessary to determine the internal error or error before rounding. Two methods may be used: (1) the enhanced resolution of the device; or (2) the "small weights" method (weights equal to no more than 1/10 of the value of the verification scale interval). 15.1 Enhanced resolution If the device has a resolution-enhancing feature (multiplied by 10 or more), this feature will be used during testing. 15.2 "Small weights" method Also known as "flip weights" or "break point determination", by applying small weights equal to 1/10 d a device and observing the point at which it begins to change from one indication to the next, one can determine the internal resolution of the device down to 1/10 of its normal indication. For example, to determine the internal error on a 50 kg x 10 g device, small weights of 1 g will be used. To determine the break point of a particular reading, first start with only the known weight on the scale. For example, 10 kg on a 50 kg x 10 g scale. The scale will read 10.00 kg. One at a time, place 1 g of weights on the scale, pausing in between each application. During this pause, observe the indication. If it is now displaying 10.01 kg, stop and record the amount of weight you've added to the scale. If it is alternating between 10.00 kg and 10.01 kg, continue adding weights until it is stable and record the total weight added. Calculation of internal errors. To calculate the internal error, it is assumed that the zero reference point is at the mid range of the interval, that is that the scale is rounding properly and that it will change from one indication to the next exactly halfway between those two indications. The error is therefore determined by dividing the division size by 2 and subtracting the value of the small weights from the pervious step. To continue the previous example, assume we added 4g to the scale before it began to display 10.01 kg in a stable manner. The error is therefore ( ) ggg 142/10 =− . 16.0 Increasing and decreasing load tests - selection of loads The increasing and decreasing load tests are procedures required to determine the performance characteristics of weighing devices or major components tested separately. These tests are performed several times during the evaluation at room temperature and at prescribed extremes of temperature (generally -10°C, 20°C and 40°C). At least five known increasing and decreasing test loads (preferably 10 loads), ranging between zero and the maximum capacity, will be applied. The internal error before rounding will be determined for each load unless the error is well within the limits of error.



Known test loads will be selected whose value corresponds as much as possible to the turning points of the limits of error (see items 1, 2 and 3 of the graph in point 14.1 above). These are the critical points where the device is most likely to fail. 17.0 Sequence of tests The tests described in this manual and the order in which they are to be carried out must be followed as closely as possible. The sequence of tests has been established to simplify the procedure as a whole and to minimize the time required to complete full evaluation of devices. The order in which the tests are to be carried out is given in Part 3 of this manual. 18.0 Adjustment and Calibration of the Device During Evaluation 18.1 General The device will be calibrated as close to zero error as possible before the test program begins, and thereafter, if necessary, only as indicated in the recommended test sequence in Part 3 of the manual. Unless otherwise indicated by the applicant or the manufacturer, the device will be calibrated as close to zero error as possible at 70% of its maximum capacity. 18.2 Adjustment of calibration points Electronic indicating elements evaluated separately Calibration points normally serve to correct linearity errors of load receiving/weighing elements to which indicating elements are connected. The calibration points of indicating elements tested separately will be set at zero or inhibited. The indicating element will be adjusted to the maximum number of verification scale intervals "e" (counts) requested by the applicant, within the limits imposed by the class of the device. Complete devices The linearity of complete weighing devices will be set as close to zero error as possible at the appropriate time by means of the calibration points. Weighing elements tested separately The calibration points of a high precision indicating element used as standard for the evaluation of a weighing element will be set to zero effect or inhibited. 18.3 Temperature of device at time of adjustment All adjustments before and during evaluation will be made with the device at room temperature (≈20°C). 18.4 Warm-up of device before testing The performance of some devices is sometimes affected when the internal temperature (electronic components) varies and is not stable. When a device is unplugged for a length of time and then plugged in again, the manufacturer usually recommends allowing the device to warm up before being used. The device should have a mechanism to prevent the display and printing of weights until the internal temperature is sufficiently stable to allow accurate measurement. The technologist will conduct the test as soon as the device displays a weight value.



18.5 Pre-loading (exercising) the device before testing After the device has been assembled and installed, and whenever it is moved and reinstalled, it may be loaded, if necessary, up to its full capacity to "exercise" the load cell or cells before testing. The recommended test sequence and the test procedures described in Part 3 of this manual provide information as to when it is necessary and permitted to "exercise" the device. 18.6 AZSM/AZT adjustment Unless otherwise indicated in the description of the test procedures, if the device is equipped with AZSM/AZT, the AZSM/AZT will be set at the minimum value. If the minimum value is zero, the AZSM/AZT will be set at zero. Where a particular procedure specifies that the AZSM/AZT is to be deactivated and the device does not allow this to be done easily, the effect of the mechanism will be cancelled by applying a small load (10 d) to conduct the tests. 19.0 Devices equipped with IZSM Some devices are equipped with IZSM. This feature allows rough setting of the zero according to the weight of the platter, platform or load receiving element. This setting operation occurs automatically whenever the device is turned on or plugged in. The IZSM range is usually limited to 20% of the device capacity, but may range up to 100%. The load cells of such devices are likely to operate over a much wider range than the capacity marked on the device. The technologist must therefore perform appropriate tests to ensure that the performance of the device is acceptable over its whole extended capacity. When the IZSM limit is 20%, the largest load to which the device will be subjected will be 120% of the capacity (capacity + 20%). In this case, all the tests will be carried out while the IZSM is at the maximum (20%). When the IZSM limit is 100%, the largest load to which the device will be exposed will be 200% of the marked capacity (capacity + 100%). When the IZSM capacity exceeds 20%, the increasing and decreasing load tests (linearity, hysteresis and repeatability) at room temperature will be performed twice, that is, when the IZSM is at minimum capacity (0%) and maximum capacity (100%). All other tests, including the tests for susceptibility to temperature variations (-10°C and 40°C) will be performed while the IZSM is at maximum capacity (100%). The possible adjustment of the IZSM of a separately approved indicating element must not exceed 20% of the maximum approved capacity of the indicating element, because the performance of the load receiving/weighing elements to which it will be associated is not known. 20.0 Control of the environment The environment in which the tests will be carried out is considered constant and suitable when:

• temperature variations during testing do not exceed 2.5°C (total range); • the relative humidity is sufficiently constant that no condensation is observed on the device or the

standard weights during testing; and • the relative humidity does not exceed 50 %.

During temperature variation susceptibility testing, the rate of passage from one temperature to another must not exceed 1°C per minute. For a given influence test, one factor is varied at a time (temperature, humidity) while the others are kept constant.



21.0 Separate testing of electronic indicators - method and equipment Electronic indicating elements may be tested in one of the following ways:

• connected to a suitable load receiving/weighing element; • connected to a load-cell simulator; • connected to a load cell placed in a calibrated dead load tester.

The preferred method is that involving the use of a load receiving/weighing element, because, unlike the load-simulator method, it can be used to carry out the whole test program. 21.1 Tests using a load receiving/weighing element or load cell installed in a dead load tester The accuracy of the load receiving/weighing element or the load cell as regards linearity, repeatability and hysteresis must allow proper evaluation of the indicating element. The intrinsic errors of the load receiving/weighing element or the load cell must not lead to rejection of the indicating elements under assessment. The performance of the load receiving/weighing element or the load cell must first be checked using a suitably calibrated high-precision reference indicator. The maximum combined linearity, repeatability and hysteresis error must not exceed 70% of the limits of error allowed for a complete device (Except a weighing element that is the only element likely to produce measurement errors; for instance a weighing element that produces digital signals interpretable by a computer software would be given full limits of error). During testing, the load receiving/weighing element or the load cell will be kept at constant temperature and humidity. 21.2 Simulator tests The accuracy of the simulator must first be checked to ensure that the intrinsic errors are minimal and will not cause rejection of the indicating element, and that its overall performance makes it possible to properly determine the performance of the indicating element. The linearity and hysteresis of the simulator must therefore be checked first by means of a calibrated high-precision electronic indicator. During testing of the indicating element, the simulator will be kept at constant temperature and humidity. The precision simulator used depends on the type of excitation current for which the indicating element is set. 22.0 Standard Test Plans The following table lists the tests to be performed on new devices submitted for approval and also for common revisions to existing approvals. Due to differences in design, some tests may not be applicable to all devices.



Table 4: Standard test plans for new approvals

Device Type Required Tests - Part 2 Required Tests - Part 3

Complete Device All Sections • LG-3.01 - Linearity, Hysteresis and Repeatability at Ambient Temperature

• LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity (Section/Shift Tests) • LG-3.04 - Tilting (Off Level Position) • LG-3.05 - Suitability of the Level Indicator • LG-3.06 - Warm up Time • LG-3.07 - Power Interruption • LG-3.08 - AC Voltage Variations • LG-3.09 - DC Voltage Variations • LG-3.10 - Immunity to Radiated Electromagnetic Fields • LG-3.11 - Susceptibility to Magnetism - Magnetic Loads

(EMF load cells) • LG-3.12 - Susceptibility to Magnetism - Ferromagnetic Plate

(EMF load cells) • LG-3.13 - Temperature Effect on Linearity, Hysteresis and

Repeatability • LG-3.14 - Creep and Creep Return to Zero • LG-3.15 - Temperature Effect on No-Load Indication • LG-3.20 - Endurance Test • LG-3.21 - Portability Test (if not permanently installed)

Indicator All sections except: • Section 11 - Load

Receiving Element • Section 19 - Tilting

• LG-3.01 - Linearity, Hysteresis and Repeatability at Ambient Temperature

• LG-3.06 - Warm up Time • LG-3.07 - Power Interruption • LG-3.08 - AC Voltage Variations • LG-3.09 - DC Voltage Variations • LG-3.10 - Immunity to Radiated Electromagnetic Fields • LG-3.13 - Temperature Effect on Linearity, Hysteresis and

Repeatability • LG-3.15 - Temperature Effect on No-Load Indication • LG-3.21 - Portability Test (if not to be permanently installed)

Weighing / Load Receiving Element

• Section 1- Markings • Section 2 - Sealing

(Smart Load Cells, Junction Boxes)

• Section 11 - Load Receiving Element

• Section 12 - Relationship of Vmin and d (MRA only)

• Section 19 - Tilting


• LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity (Section/Shift Tests) • LG-3.04 - Tilting (Off Level Position) • LG-3.05 - Suitability of the Level Indicator • LG-3.06 - Warm up Time (separately powered LREs) • LG-3.08 - AC Voltage Variations (separately powered LREs) • LG-3.09 - DC Voltage Variations (separately powered LREs) • LG-3.10 - Immunity to Radiated Electromagnetic Fields

(Smart Load Cells) • LG-3.11 - Susceptibility to Magnetism - Magnetic Loads



Repeatability • LG-3.14 - Creep and Creep Return to Zero • LG-3.15 - Temperature Effect on No-Load Indication • LG-3.20 - Endurance Test • LG-3.21 - Portability Test (if not to be permanently installed)



Table 5: Standard test plans for revisions

Revision Type Required Tests - Part 2 Required Tests - Part 3

New Load Cell • Section 12 - Relationship of Vmin and d (MRA only)


• LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity (Section/Shift Tests) • LG-3.04 - Tilting (Off Level Position) • LG-3.05 - Suitability of the Level Indicator • LG-3.06 - Warm up Time • LG-3.07 - Power Interruption • LG-3.08 - AC Voltage Variations • LG-3.09 - DC Voltage Variations • LG-3.10 - Immunity to Radiated Electromagnetic Fields • LG-3.11 - Susceptibility to Magnetism - Magnetic Loads



Repeatability • LG-3.14 - Creep and Creep Return to Zero • LG-3.15 - Temperature Effect on No-Load Indication • LG-3.20 - Endurance Test • LG-3.21 - Portability Test (if not permanently installed)

New Display • Section 3 - Indication and Registration

• Section 5 - Values Defined

• Section 6 - Agreement of Registrations

• Section 10 - Indicating Zero and Negative

• Section 14 - Limits of Indication

• Section 23 - Devices Used for Direct Sale to Public (if applicable)


• LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity • LG-3.08 - AC Voltage Variations • LG-3.09 - DC Voltage Variations • LG-3.13 - Temperature Effect on Linearity, Hysteresis and

Repeatability • LG-3.15 - Temperature Effect on No-Load Indication

New Housing • Section 1 - Markings (for permanence of label)

• Section 2 - Sealing


• LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity • LG-3.10 - Immunity to Radiated Electromagnetic Fields • LG-3.13 - Temperature Effect on Linearity, Hysteresis and

Repeatability • LG-3.14 - Creep and Creep Return to Zero • LG-3.15 - Temperature Effect on No-Load Indication

New Platter (size) • Section 11 - Load Receiving and Weighing Element

• LG-3.01 - Linearity, Hysteresis and Repeatability • LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity

New Platter (design) • Section 11 - Load Receiving and

• LG-3.01 - Linearity, Hysteresis and Repeatability • LG-3.02 - Load Discrimination



Weighing Element • LG-3.03 - Eccentricity

• LG-3.13 - Temperature Effect on Linearity, Hysteresis and Repeatability

• LG-3.14 - Creep and Creep Return to Zero • LG-3.15 - Temperature Effect on No-Load Indication

New Power Supply • Section 1 - Markings • LG-3.01 - Linearity, Hysteresis and Repeatability • LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity • LG-3.08 - AC Voltage Variations • LG-3.09 - DC Voltage Variations

New Unit of Measure • Section 1 - Markings • Section 3 -

Indication and Representation

• Section 5 - Values Defined

• Section 6 - Agreement of Registrations

• Section 7 - Price Computing Feature

• Section 14 - Limits of Indication

• LG-3.01 - Linearity, Hysteresis and Repeatability • LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity

Table 6: Standard test plans for field tests

Device Type Required Tests - Part 2 Required Tests - Part 3

On-Board Weighing Systems

• Section 1- Markings • Section 2 - Sealing • Section 14 - Limits of

Indication • Entry of Keyboard

Tare or Manual weight prohibited

• Forklift devices - blanking display if forklift is in motion and LG-18.01


• LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity (Section/Shift Tests) • LG-3.04 - Tilting (Off Level Position) • LG-3.14 - Creep and Creep Return to Zero • (Not applicable to dynamic devices - Wheel Loaders) • LG-3.20 - Endurance (Permanence) Test • Following tests are for dynamic devices only (Wheel

Loaders): • RPM Test • Bounce Test 30 minute re-zero requirement and zero after transaction

Truck Scales • Section 1- Markings • Section 2 – Sealing • Section 14 - Limits of

Indication


• LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity (Section/Shift Tests) • LG-3.14 - Creep and Creep Return to Zero

Hopper Scales • Section 1- Markings • Section 2 – Sealing • Section 11 - Load Receiving/Weighing Element


• LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity • LG-3.14 - Creep and Creep Return to Zero

Electronic Load Receiving and Weighing Element

• Section 1- Markings • Section 2 – Sealing • Section 11 - Load

Receiving/Weighing Element


• LG-3.02 - Load Discrimination • LG-3.03 - Eccentricity • LG-3.14 - Creep and Creep Return to Zero



Revision Rev.1 (September 2009) Typographical correction Rev.2 (March 2010) Added definition for AZT, AZSM redefined Rev.3 Added Part 22 – Standard Test Plans Rev.4 (May 2013)

• Removed some images for online publishing • Re-worded "small weights" method section


Part: 2 Section: ToC Evaluation of metrological Features - Table of Contents

Part 2 - Evaluation of metrological Features - Table of Contents Subject Section Marking - Generalities .......................................................................................................................... P2_S1 Sealing ................................................................................................................................................. P2_S2 Indication and Registration - Representation ....................................................................................... P2_S3 Recorded Representation (printed) ...................................................................................................... P2_S4 Values Defined ..................................................................................................................................... P2_S5 Agreement of Registrations .................................................................................................................. P2_S6 Price Computing Feature ..................................................................................................................... P2_S7 Recorded Representation of Gross, Tare and Net Weights ................................................................ P2_S8 Manual Weight Entries ......................................................................................................................... P2_S9 Indicating Zero and Negative Values ................................................................................................. P2_S10 Load Receiving/weighing Element ..................................................................................................... P2_S11 Load Cell - Relationship of Vmin and d ................................................................................................ P2_S12 Damping Means and Up-dating Rate of Weight/price Data ............................................................... P2_S13 Limits of Indication.............................................................................................................................. P2_S14 Zero Setting Mechanisms .................................................................................................................. P2_S15 Available Section ................................................................................................................................ P2_S16 Tare .................................................................................................................................................... P2_S17 Motion Detection ................................................................................................................................ P2_S18 Tilting (Off-level Effect) ....................................................................................................................... P2_S19 Segment Verification .......................................................................................................................... P2_S20 Multiple Deck Weighing Systems ....................................................................................................... P2_S21 Multi-interval Devices and Multiple Range Devices ........................................................................... P2_S22 Devices Used for Direct Sale to the Public......................................................................................... P2_S23 Weigh-in/weigh-out Systems .............................................................................................................. P2_S24 Non Metrological Functions ................................................................................................................ P2_S25 Abbreviations and Symbols ......................................................................................................... Appendix 2A Revision Original document


Part: 2 Section: 1 Marking

Reference

Sections 49 to 54 of the Specifications Relating to Non Automatic Weighing Devices (1998)

1.0 Marking – Generalities

Complete weighing devices and major components (indicating elements and load receiving/weighing

elements) of devices tested separately must be marked with certain information in the manner required by the

Specifications Relating to Non Automatic Weighing Devices (1998). Complete devices in the same housing

or made of non detachable major components are only required to bear one series of markings. Major

components of complete devices must be marked individually if they can be separated and interfaced

(mixed/matched) to other major components to form a device. Major components submitted for approval

evaluation individually are tested separately and are also required to be marked individually.

Remote (secondary) weight displays, slave modules such as printers, keyboards, cash registers and other

similar modules that are used in conjunction with approved devices are not required to be marked if they

perform no significant metrological functions.

1.1 Marking - Complete Devices

This section applies to complete devices in the same housing or complete devices made of major detachable

components interfaced together and not intended to be separated and used in conjunction with other

individually approved major components to form different devices. For such devices, only one series of

information is required.

The device must be marked with:

1.1.1 the name or trademark of the manufacturer or applicant.

1.1.2 a model designation that positively identifies the device type or design.

1.1.3 a distinctive serial number. The serial number must be prefaced by words, an abbreviation or a

symbol that clearly identifies the number as the serial number.

1.1.4 the appropriate Measurement Canada approval number. The approval number must be prefaced

with words or an abbreviation that positively identifies the number as the Canadian approval number.



Acceptable solutions

• Canadian Approval AM-4145

• MC AM- 4145

• CND W&M AM-4145

• AM-4145

1.1.5 the accuracy class. The numerals I, II, III, III HD or IIII are the markings required to indicate the

accuracy class. The numeral within an ellipse or a figure approximating an ellipse is the proper way

to indicate the accuracy class. The word "Class" followed by the numeral is also acceptable.

1.1.6 the maximum capacity (Max) that the device can weigh.

1.1.7 the value of the actual scale interval "d".

1.1.8 the value of the verification scale interval "e", if different from "d". On Class III, III HD and IIII

devices, multi-interval and multiple range devices, "e" must equal "d".

Note 1: Max, “d“ and “e“, if different from “d“, must be marked near the weight display.

Note 2: If a device has a separate display for customers, Max, “d“ and “e“, if different from “d“, must

be marked near both the operator and the customer weight displays.

Note 3: Max, ”d“ and ”e“, if different from ”d“, must be marked for all weight units that can be

displayed (i.e., pounds and kilograms). If the device can be configured to multiple units, but

has no unit switching, then it may list either all units it can be configured for, or just the

units it is currently configured for.

Examples

10 kg x 5 g Max 10 kg/20 lb 10 kg (20 lb) x 5 g (0.01 lb)

20 lb x 0.01 lb d = 5 g/0.01 lb

Note 4: The markings of Max, “d” and “e”, if different from “d”, near the weight display must reflect

actual device operation. For instance, a device that is capable of being configured for either

single or multiple range operation must be marked to reflect the configuration selected.

1.1.9 the operating temperature range if different than -10°C to 40°C. For Class I devices, the

temperature range must be at least 5°C; for Class II devices, at least 15°C; and for Class III, III HD

and IIII devices, at least 30°C.



Note 5 Multiple range and multi-interval devices must be marked with the weight ranges and the

corresponding scale intervals. Devices with more than one class designation must be

marked with each class designation in clear association with Max, ”d“, ”e“ (if different from

“d”) and the temperature range, if they are different for each class.


For multi-interval devices

0-3 kg (0-6 lb) x 1 g (0.002 lb) or Max 3/6 kg (6/15 lb)

3-6 kg (6-15 lb) x 2 g (0.005 lb) d = 1/2 g (0.002/0.005 lb)

For devices with more than one weighing range

W1 W2

Max 3 kg 6 kg

(6 lb) (15 lb)

d = 1 g 2 g

(0.002 lb) (0.005 lb)

For devices with weighing ranges in different accuracy classes and restricted temperature ranges.

W1 W2

Max 3 kg 15 kg

d = 0.01 g 10 g

e = 0.1 g e = d

10°C/30°C 0°C/35°C

1.1.10 the verification marks. The device must have an area, either on the marking plate itself or on the

device adjacent to the marking plate, suitable for the application of the verification marks. The

surface of this area must be at least 1.3 x 2.5 cm (½" x 1").



1.2 Marking - Indicating Elements

This section applies to indicating elements that are evaluated and tested separately. Such indicating

elements are either submitted to approval evaluation separately or are major detachable components of a

complete device and are intended to be used in conjunction with approved and compatible weighing elements

to form different devices.

The indicating element must be marked with:







See acceptable solutions in section 1.1.4.


accuracy class. The numeral within an ellipse or a figure approximating an ellipse is the proper way

to indicate the accuracy class. The word "Class" followed by the numeral is also acceptable.

1.2.6 the maximum number of scale intervals (nmax). If the indicating element is approved for two

accuracy classes and has a different maximum number of scale intervals for each accuracy class,

both maxima must be marked in clear association to the accuracy class designation.


Class III / III HD

nmax 3 000 / 8 000

nmax 3 000 8 000

nmax 3 000



nmax 8 000

1.2.7 the maximum capacity "Max", the value of the actual scale interval "d" and the value of the

verification scale interval "e", if different from "d". This information must be marked on the

indicator near the weight display when it is interfaced with a weighing element to form a device.

This marking reflects the limitation of the complete weighing device. The technologist (ASL) will,

however, ensure that indicators have provisions for the marking of this information. See the Notes

and examples below sections 1.1.8 and 1.1.9.

Note: for multiple range devices, multi-interval devices and indicators with more than one accuracy class

designation, see the Note below section 1.1.9.

1.2.8 the operating temperature range, if different than -10°C to 40°C. For Class I indicators, the

temperature range must be at least 5°C; for Class II indicators, at least 15°C; and for Class III, III

HD and IIII indicators, at least 30°C.

1.2.9 the verification marks. The indicator must have an area, either on the marking plate itself or on the

indicator adjacent to the marking plate, suitable for the application of the verification marks. The

surface of this area must be at least 1.3 x 2.5 cm (2" x 1").

1.3 Marking - Software

1.3.1 For software that is evaluated separate from hardware, the identifying information (manufacturer

name, model number and approval number) must be visible on the video display terminal or

printable when called up from the menu, or be continually displayed. For further information

regarding the approval evaluation of software, the Specifications Relating to Metrological Software on

Measurement Canada=s Web site must be consulted.

1.4 Marking - Load Receiving/Weighing Elements

This section applies to weighing elements that are evaluated and tested separately. Such weighing elements

are either submitted to approval evaluation separately or are major detachable components of a complete

device and are intended to be used in conjunction with approved and compatible indicating elements to form

different devices.



The weighing element must be marked with:







See acceptable solutions in section 1.1.4.


accuracy class. The numerals within an ellipse or a figure approximating an ellipse is the proper way

to indicate the accuracy class. The word "Class" followed by the appropriate numerals is also

acceptable.

1.4.6 the maximum capacity (Max) that the weighing element can weigh.

1.4.7 the value of the minimum verification scale interval (emin) for which the weighing element complies

with the requirements and can be set.

1.4.8 the maximum number of scale intervals (nmax) for which the weighing element complies with the

requirements and can be set.

1.4.9 the operating temperature range, if different than -10°C to 40°C. For Class I weighing elements,

the temperature range must be at least 5°C; for Class II weighing elements, at least 15°C; and for

Class III, III HD and IIII weighing elements, at least 30°C.

1.5 Marking - Load Cells

The marking of load cells is not required at this time.

1.6. Marking - Readability, Location and Permanence

1.6.1 The required information must be complete, legible, accessible and durable. If necessary for clarity,

there must be defining words or authorized symbols associated with the numbers (i.e., model

numbers, temperature range, etc.). See the list of acceptable defining words and symbols in

Appendix 2-A. It is recommended that the height of capital letters be at least 2 mm (OIML R76-1).



1.6.2 The required information must be appropriately located. Markings may be on either a marking plate

affixed to a permanent part of the device, on the device itself, or both. Information that identifies the

device (manufacturer name or trademark, model, serial and approval numbers) should be grouped

together. Max, ”d“ and ”e“ (if different from ”d“) must be marked near the weight display(s). See

the Note below sections 1.1.8 and 1.1.9 for additional information.

1.6.3 The marking must be visible without having to remove a permanent part of the device or having to

move or lift the device. Markings must be available with minimum effort and be accessible without

disassembly requiring the use of special tools or equipment.

Acceptable locations

1. Markings (and/or the marking plate) may be located on the top, sides or front of the device.

Markings may be located beneath the platter and fastened to the scale structure if the platter is

easily removable (small devices such as computing scales and bench scales).

2. Weighing elements. The required information must be on a surface that is an integral part of the

chassis. If the information is on a label or a plate, it must be permanently attached to the device.

A plate may be riveted or welded but not affixed with bolts or screws.

3. Weighing elements of large scales. Identification information for the weighing elements of vehicle,

axle load, floor, livestock, railroad track and large hopper or tank scales must be located near the

point where the signal leaves the weighing element (this would be the transverse lever on a

mechanical scale and on, or near, the junction box on an above ground scale). In the case of built-

in weighing elements (flush mounted), the required information can be placed on the scale chassis

and be accessible by the removal of a cover plate.

Unacceptable locations

Under the scale; inside a cabinet; on the back of the device or indicating element if it is difficult to move and

is likely to be located near a wall; marking plate affixed to the platter.



1.6.4 If Max, ”d“ and ”e“, if different from ”d“, are displayed electronically, such as on a video display

terminal, then they must be adjacent to the weight display and continuously displayed when the

system is in the weighing mode.

1.6.5 The lettering must be permanent. This requirement also applies to words and symbols for

measurement units adjacent to the weight display and to words and symbols that identify or indicate

the status of metrologically significant annunciators. Perform the test described in LG 1.01 and grade

the permanence of marking.

1.6.6 Plates or other materials (decals, labels or badges) on which the required information is marked

must be made of durable material and permanently affixed to the device so that they cannot be

easily removed and affixed to another device. Perform the test described in LG-1.02.

1.7 Marking - Special Applications

Certain device types are designed for specific applications. Such devices may incorporate features, perform

certain functions or operate in a particular fashion that would not be acceptable for all applications. Since

these devices may not meet all the usual requirements, their use is restricted to the specific applications for

which they were designed. The device restriction must therefore be permanently and clearly marked adjacent

to both the operator and customer weight displays.

Some examples:

Weight Classifiers Digital weight classifiers round weight values up to the next scale interval. They are

designed to classify packages within price ranges for shipping, courier or postal applications. Weight

classifiers would therefore not be appropriate for use in grocery store applications. Their use is restricted and

they must be marked with the following: << Weight classification only >> or << Weight classifier >> or <<

Postal scale >>.

Industrial devices Certain devices are designed for industrial applications. They do not incorporate

features that are normally required for devices used in direct sales to consumers. For instance, they may not

have a display for consumers; the tare feature may not comply with the requirements for devices used in

direct sale applications, etc. These devices, if they resemble devices intended to be used in direct sale

applications, must be marked as follows to indicate that they are designed for industrial use only: <<Not for

use in direct sale to the public>> or similar language.

1.7.1 The device is marked with the appropriate restriction.



1.8 Marking - Operational Controls, Indications and Features

The marking of operational controls such as keys, push buttons and switches that are strictly for operator use

is not required by Measurement Canada. Keys that are visible only to the scale operator need only be

marked to the extent that a trained operator can understand the function of each key. It is however

recommended that internationally recognized words and symbols be used.

Annunciators that are "metrologically" significant must be marked with words or acceptable symbols. The

following are some examples of "metrologically" significant annunciators: centre of zero, "net", "gross" and

"tare" weight indications, identification of the weighing element in use on a multi-deck weighing system, the

range selected on a manual multiple range device, etc..

1.8.1 Annunciators for metrologically significant features are clearly and permanently marked.

LG-1.01 Permanence of the lettering

Purpose

This test is aimed at evaluating the permanence of the information to be marked on the device, or a major

detachable element evaluated separately, in order to determine if it will withstand wear and cleaning.

Markings are subjected to the following tests to simulate accelerated wear. The markings are then compared

to a typical set of markings exhibiting various degrees of wear, graded from excessive unacceptable wear (1)

to minimal effect (7).

Application

This test is to be applied to all mandatory markings including the manufacturer's name, the model and serial

numbers, Max and ”d“, the unit of measurement associated with weight indications (kg, lb), to other words or

symbols associated with metrologically significant annunciators, etc..

Test Procedure



Attempts are made to remove the marked information, whether on a badge (plate) or on the device itself,

using the following means:

A. Rub over one letter of the marking twenty (20) times using an ink eraser in the same manner and with the same force as one would normally exert while erasing an inscription written with a ballpoint pen.

Note: For consistency of application, the laboratories use Eberhard Faber ink eraser type # 101,

but any blue, hard rubber eraser is acceptable. B. Clean (rub 20 times) with the following cleansers which are presumed to be readily available:

1. Cleansing liquid and a damp cloth 2. "Soft" household cleansing powder and a damp cloth 3. Window cleansing fluids and a damp cloth

Note: Any brand of cleansing powder is acceptable (such as Ajax and Comet), if, at a minimum,

it contains an abrasive and a detergent/surfactant. For consistency of application, the laboratories use the Windex brand of product for the test in part B.3.



Figure 1: Samples of various degrees of wear

Interpretation of Results

The information marked on the label is deemed to be permanent if, after the test, the label receives a

grading of four (4) or higher (see the sample on the next page).

LG-1.02 Plate, decal - permanence of installation and durability of the material

Purpose



To determine whether the label bearing identification markings (manufacturer's name, model and serial

numbers, approval number, initial inspection marks or label) is permanently affixed to the device.

Test Procedure

An attempt is made to remove the specimen label(s) from the device by pulling it off or by prying off a metal

badge that is only attached using adhesive. Any means of removal are allowed while a deliberate effort to

conceal the removal is made. Such an attempt shall be made at either -10oC and 40oC or at the minimum

and maximum operating temperatures specified by the manufacturer.


An identification label is deemed to be permanently affixed to the device if it cannot be removed from the

device and installed on another device without exhibiting readily observable signs of tampering. Acceptable

indications of tampering are the destruction of the badge by tearing, permanent or extensive wrinkling, or the

repeated exposure of the word "VOID" upon removal of the badge.

Note 1 A plate that is riveted to the device is deemed to be permanently fastened if the part of the

device to which it is attached is not removable.

Note 2 For information such as lb/kg, motion annunciator, centre of zero annunciator, tare/net

annunciator, Max, “d“ and ”e“ (if different from ”d“) near the weight display, etc. (other than

the identification markings: manufacturer=s name, model, serial and approval numbers), a

sticker that is sturdy and will not detach when subjected to the normal conditions of use of

the device (heat, cold, humidity, cleaning) is acceptable. It does not have to be of the self-

destructive type.

Note 3 Labels that tear when removed can often be removed without breakage by affixing clear

packing tape or a clear adhesive sheet on the label prior to removal. If a label can be

removed in this fashion it is considered a non-compliance.

Revision

Original document


Part: 2 Section: 2 Sealing

Reference

• Section 48 of the Specifications Relating to Non Automatic Weighing Devices (1998) • Terms and Conditions for the Approval of Metrological Audit Trails

2.0 Sealing - Generalities Electronic weighing devices must have provisions to the effect that a security seal must be broken, or an audit trail provided, before any adjustment affecting the performance of the device can be made. Only the metrological parameters: that can affect the measurement features, that have a significant potential for fraud, whose range extends beyond that appropriate for device compliance or the suitability of the equipment, shall be sealed. 2.1 Philosophy for Sealing The judgment as to whether or not a method of access represents a "significant potential for fraud" and thus requires sealing, will be based upon the following philosophies. 2.1.1 The need to seal specific features depends upon:

a. The ease with which the feature or the selection of the feature can be used to facilitate fraud; and

b. The likelihood that the use of the feature will result in fraud not being detected. 2.1.2 Features or functions that are routinely used by the operator as part of device operation, such as

the setting and maintaining of unit prices in price look-up codes, are not sealable parameters. 2.1.3 If the selection of a parameter (or a set of parameters) would result in performance that would

obviously be in error, such as the selection of parameters for different countries, then it is not necessary to seal the selection of these features.

2.1.4 If individual device characteristics are selectable from a "menu" or a series of programming steps,

then access to the "programming mode" must be sealable. 2.1.5 If a device must undergo a physical act, such as the cutting of a wire and physically repairing the

cut to reactivate the parameter, it would be considered an acceptable way to select parameters without requiring a physical seal or an audit trail.

2.2 Sealable Parameters on Non Automatic Weighing Devices The following examples of adjustments, parameters and features to be sealed are to be considered "typical" or "normal". The list is not intended to be all inclusive and any other parameters that may affect the metrological functions of a device must be sealed. If listed parameters or other parameters which may affect the metrological function of a device are not to be sealed, the manufacturer must demonstrate that the parameter will not affect the metrological performance of the device. Typical Sealable Parameters

• Coarse zero • Span • Linearity correction points



• Motion detection (on/off, bandwidth) • Scale interval “d“ (or location of the decimal point) • Number of scale intervals • Range of overcapacity • Manual weight entries (on/off) • AZSM (on/off and range of a single step) • Zero and AZSM total range (if the range can be set for more than 4% and if this increases the

weighing capacity) • Filter (number of samples averaged for weight readings) • Filter (averaging time for weight indications) • Units of measurement (if not displayed or printed on the primary register),

Typical Features or Parameters that are Not Required to be Sealed

• Product codes • Commodity unit prices • Zero and AZSM total range (if the range can be set for more than 4% but this does not increase

the weighing capacity) • Display update rate • Selection of tare feature operation (keyboard, push button or automatic tare (on/off)) • Weigh-in/weigh-out operation (on/off)

2.3 Other Mechanisms Requiring Sealing 2.3.1 Junction boxes that have adjustment parameters (potentiometers, rheostats, resistors or software

configuration, etc.) must have provisions for applying security seals. 2.3.2 In the case of a complete scale consisting of an electronic indicator and a load receiving element

incorporating a junction box or load cells that have built-in calibration/configuration capabilities, and for which the parameters can be changed "remotely" through the indicator keyboard, there must be provisions to seal load cell cables to the indicator and junction box.

2.3.3 If the device is equipped with an automatic or semi-automatic calibration mechanism, the

mechanism must be inside the device and there must be provisions to apply security seals so that neither the mechanism nor the calibration process can be altered.

Note: Automatic and semi-automatic calibration mechanism An automatic or semi-automatic calibration mechanisms are allowed provided it is within the device and the method or process can not be tampered with. Using the calibration mechanism, try to calibrate the device: when off level, when there is a load on the platform, and when the display device is in motion. Also try to put a small load on the set when the internal mechanism calibrates. These interventions should give rise to any erroneous calibration. 2.4 Physical Seals Physical seals comprise “lead“ and wire seals, pressure sensitive seals, etc. They may be used to seal certain device categories, features and mechanisms (see sections 2.3 and 2.5). 2.4.1 Seals must be readily accessible and observable. Devices must be sealable in a manner that

does not require disassembly or moving of the device to gain access to the adjustments. However, removing a protective cover plate to access a junction box is acceptable. The removal of a cover plate must be simple and not require excessive effort or the use of special tools.



2.4.2 On small devices (portable) the means of sealing may be under the platter, if the platter can be

lifted easily, under the scale or at the back of the scale if the scale is designed so that it can be turned upside down without damage to remove or apply security seals. When a Alead@ and wire seal is located under the platform, there must be ample clearance to eliminate the possibility of interference between the seal and the platform.

2.4.3 When two bolts are used for a ”lead and wire seal“, it must be impossible to remove either bolt

without breaking the wire seal. A free standing bolt (a bolt which passes through a panel and is fixed in place with a nut on the opposite side of the panel) is not acceptable.

2.4.4 Pressure sensitive seals are acceptable under certain conditions. If they cover a hole (e.g.,

through which a "calibration enable" switch would be activated) the hole must be covered with a suitable rigid plug. The seal must not bridge so as to leave cavities or air pockets under the seal. Cavities and air pockets are weak points that could cause the seal to be easily damaged (see the illustration below).

1 Pressure sensitive (paper) seal 2 Keylock 3 Air pocket (void space) 4 Casing 2.4.5 A pressure sensitive security seal is not suitable in an adverse environment (rain, cold, wash-

down, etc.). 2.5 Sealing Electronic Devices Electronic devices must be "sealed" in accordance with the minimum requirements contained in the Specifications Relating to the Design, Composition, Performance and Use of Metrological Audit Trails. Note : A Category 1 or Category 2 device may be sealed using an event logger instead of a physical

seal. An event logger exceeds the minimum requirements for Category 1 and Category 2 devices.

The terms used in the Notice of Approval are defined in the Terms and Conditions for the Approval of Metrological Audit Trails; these Terms and Conditions can be found on the Measurement Canada’s website. Note : Numbers in parentheses refer to section numbers in the Terms and Conditions.



2.5.1 Category 1 Device A device that does not have remote configuration capability. Usually a device of this category has internal, physical means of adjustment such as dip switches, or configuration and adjustments can only be made through the device keypad when it is in a "calibration" mode. Such device may be sealed by means of a physical seal or two event counters: one for calibration parameters and one for configuration parameters. 2.5.1.1 (3.1) Access to sealable parameters is protected by:

a) a physical seal; or b) an audit trail with two event counters (one for calibration, the second for configuration).

2.5.2 Category 2 Device A device offering remote configuration capability for its sealable parameters and providing sealable enabling/disabling hardware to control remote configuration use. Usually, a device of this category can be adjusted through the device keypad, remotely through the ports using an external apparatus such as a computer or using an external device such as an infrared handheld transmitter. 2.5.2.1 (3.2) Enabling/Disabling hardware access for remote communication is located at the device. 2.5.2.2 (4.1) Access to sealable parameters is protected by:

a) a physical seal; or b) an audit trail with two event counters (one for calibration and one for configuration).

2.5.2.3 When the device is in the remote configuration mode,

(7.1, i) it does not indicate nor record values; or (7.1, ii) it provides a clear and continuous indication that the device is in remote configuration mode.

2.5.3 Category 3 Device A device that provides unrestricted access to its sealable parameters. These are complex devices that are often part of sophisticated systems. 2.5.3.1 (3.3) Access to sealable parameters is protected by an event logger. 2.5.4 Event Counters If the device is “sealed” by means of event counters, the following requirements must be met: 2.5.4.1 (4.1) Two event counters: one for calibration parameters and one for configuration parameters. 2.5.4.2 (4.2) Event counters are non-resettable and have a capacity of at least 1000 values (ex. 0 to 999). 2.5.4.3 (4.3) Event counters increment appropriately.

Clarification: counters may increment once per menu access, even if multiple parameters are changed

2.5.4.4.1 (8.1, i) Information stored in non-volatile memory and retained for at least 30 days while

the device is without power. 2.5.4.4.2 (8.1, ii) protected against erasure or modification.



2.5.4.5 (9.1) Audit trail information must be readily accessible and easily readable. 2.5.4.6 (9.2) Accessing the audit trail information for review shall be separate from the calibration mode. 2.5.4.7 (9.3) Accessing the audit trail information for review must not affect normal operation of the

device. 2.5.4.8 (9.4) Accessing the audit trail information shall not require removal of any parts other than normal

requirements to inspect the integrity of a physical security seal. (e.g., a key to open a locked panel may be required).

2.5.5 Event Loggers If the device is “sealed” by means of an event logger, the following requirements must be met: 2.5.5.1 (5.1) Event loggers contain as a minimum: a count of the events, date and time, parameter

identification, and new value. 2.5.5.2 (5.1.1) Information is automatically entered in the event logger each time a sealable parameter is

changed. 2.5.5.3 (5.1.2) Irrelevant information is excluded when event loggers contents are displayed or printed. Note: Relevant information is only the parameter that is changed. Irrelevant information includes

non-metrological parameters and metrological parameters that have not been modified. 2.5.5.4 (5.1.3) Event counter increments once for each change. 2.5.5.5 (5.1.4) The date includes the year, month and day; the time includes the hour and minutes;

information is presented in recognizable format. 2.5.5.6 (5.2) A hard-copy printout of the contents is available upon demand as required. 2.5.5.7 (5.3) Event logger has the capacity of at least ten times the number of sealable parameters. 2.5.5.8 (5.3.1) The event logger drops the oldest event when the memory capacity is full and a new entry

is saved. 2.5.5.9 (5.3.2) Event counter continues to increment to capacity (1000 values). 2.5.5.10 (8.1, i) Information stored in non-volatile memory and retained for at least 30 days while

the device is without power. 2.5.5.11 (8.1, ii) protected against erasure or modification. 2.5.5.12 (9.1) Audit trail information must be readily accessible and easily readable. 2.5.5.13 (9.2) Accessing the audit trail information for review shall be separate from the calibration

mode. 2.5.5.14 (9.3) Accessing the audit trail information for review must not affect normal operation of

the device.



2.5.5.15 (9.4) Accessing the audit trail information shall not require removal of any parts other than normal requirements to inspect the integrity of a physical security seal. (e.g., a key to open a locked panel may be required).

2.5.5.16 (10.1) Displayed and/or printed information is readily interpretable by an inspector. 2.5.5.17 (10.2) Information is displayed or printed in order from the most recent to the oldest event;

and it is displayed on one line in understandable block of information. 2.6 Notices of Approval Provisions for sealing some devices or features may be complex and extensive. Certain devices may incorporate audit trails and, in addition, some of their features or mechanisms may be secured using two or more physical seals. Audit trails are also configured differently for different devices. In order to ensure adequate sealing and proper use of audit trail information, Notices of Approval should provide sealing plans and detailed audit trail operating instructions, including how to enter and exit the audit trail, for each approved model of device. Revision Original document


Part: 2 Section: 3 Indication and Registration - Representation

Reference

Sections 3, 5, 6, 30 to 38 of the Specifications Relating to Non Automatic Weighing Devices (1998)

3.0 Indication and Registration - Representation - Generalities

The Specifications require that devices be provided with indicating and recording elements appropriate in

design and amount, and that indications and recorded representations be clear, definite, accurate and easily

readable under normal conditions of use of the device. There are several requirements that must be satisfied

to facilitate the reading and interpretation of displayed weight values, while other requirements address the

proper operation of indicating and recording elements.

3.1 Value of “d” and “e”

3.1.1 The maximum and minimum number of scale intervals must comply with section 3 of the

Specifications.

3.1.2 The value of “d“ (and “e“) must be equal to 1 x 10x, 2 x 10x or 5 x 10x of a legal unit of

measurement (kilograms, grams, milligrams, pounds), where x is a negative or positive whole

number, or zero.

Clarification: if “e“ � “d“ then “e” must be equal to 1 x 10x of a legal unit of measurement, where x

is a negative or positive whole number, or zero.

3.1.3 The value of “d“ (and ”e“) of analogue indicating devices may be equal to 1/2n of a pound, ounce

or any other Canadian whole units, where n is a positive whole number (1/2, 1/4, 1/8, 1/16, 1/32

pound, ounce).

3.1.4 For Class III, III HD and IIII devices, for multi-interval devices and multiple range devices, “e” must

equal “d”.

3.1.5 On Class I or II devices, other than a multiple range or multi-interval device, “d“ may be smaller than

“e”; “e“ must be the value of the scale division immediately preceding the auxiliary reading means.



Clarification: if "e" ≠ "d" then “d” must be located to the right of the decimal point. This means

that some division sizes for “e” are not allowed when "e" ≠ "d". For example, a device with e = 1 g

and d =100 mg may not display, for a 300.1 gram weight, 300 [100] mg, but it may display

300[.1] g, with the auxiliary indicating element after the decimal point.

The values of “e” and “d” are also limited by the rule d < e <= 10d.

3.1.6 On a digital indicating device, if "e" is different from "d", "d" must be clearly differentiated from the

other figures.


1. The last digit (“d“) may be shaded.

2. The last digit (“d“) may appear in brackets.

3. The last digit (“d“) may be smaller and set apart.

3.2 Legible, Readable and Non Ambiguous

3.2.1 Indications and registrations of weights, prices, etc. must be designed and located so that reading

the results is reliable, easy and unambiguous.

3.2.2 Digits must be uniform in size, shape and character (except if “e“ � “d”).

3.2.3 Any indication of function or condition may not be represented in a manner that interferes with the

interpretation of weight. For example, a “+” or “-“ sign used as an over/under indication may not be

placed adjacent to a weight value.

3.2.4 Except for postal scales, digital weight values must be in a single unit of measure across the

weighing range. For any one indication of weight, only one unit of measure may be used.

3.2.5 Subordinate indications and recorded representations are appropriately designated or portrayed. A

decimal point or a comma must be used to set apart decimal sub-multiples of the unit.



3.2.6 A digital device must display at least one digit to the left of the decimal point or comma, and all the

digits to the right of the decimal point or comma. If a decimal point or comma is not used, at least

one active decade plus any constant (fixed) zeros must be displayed. All decades to the right of a

decimal point or comma must be active (no fixed zero).

Clarification:

Table 1: Minimum zero indication examples

Capacity Minimum zero indication

25 x 0.01 lb 0.00 lb

5000 x 1 lb 0

100 000 x 20 lb 00 lb * The last digit is a fixed zero

3.2.7 Displayed and printed values of gross, tare and net must be in the same units.

3.3 Video Display Terminal

3.3.1 If an indicator or a video display terminal provides the primary or the only weight indication for the

scale when in the weighing mode, the weight display must be a continuous live display, in an area

dedicated to the weight display, and clearly distinguished and separated from other information on

the display.

3.4 Analogue Representation - dials, beams, poises, etc.

3.4.1 Scale marks (length, width and spacing) and indicators (pointers) must be designed and assembled

so that reading the weighing results is easy and unambiguous. The overall inaccuracy of reading

shall not exceed 0.2 e (OIML R 76-1 section 4.2.1).

The following are recommended minimum design requirements to ensure accuracy of reading, and overall

accuracy of the device (compliance to 3.4.1).



Scale Marks

3.4.1.1 Scale marks must consist of lines (graduations) of equal thickness; the width or thickness of

the lines must be constant, not less than 0.2 mm and not larger than the space between

the lines.

3.4.1.2 Lines must vary in length to facilitate readings. The length of the shortest lines must be

equal or longer than the width of the clear space between the lines.

3.4.1.3 The distance between the main scale marks must be uniform to ensure a linear indication

across the scale.

3.4.1.4 The clear space between lines must be at least 0.75 mm.

Numbering

3.4.1.5 The scale interval of numbering must be constant and should not be greater than 25 times

the scale interval of the device.

3.4.1.6 If the scale is projected on a screen, at least two numbered scale marks should appear in

the projected zone.

3.4.1.7 The height and width of the numbers (real or apparent) should be proportional to the scale

marks and so that the reading of the weighing results is easy and unambiguous.

Indicator (pointer)

3.4.1.8 The width of the pointer must not exceed the width of the graduation lines and the width of

the clear space between weight graduations.

3.4.1.9 The portion of the pointer that extends along the length of graduation lines and that may be

brought into coincidence with the lines must be of the same width.



3.4.1.10 The length of the pointer must be such that the tip is at least level with the middle of the

shortest scale mark. If the pointer and the scale marks are in the same plane, the distance

between the tip of the pointer and the end of the graduation lines must not exceed 1 mm.

3.4.1.11 Parallax effects must be reduced to the practical minimum. The clearance between the

pointer and the scale marks should in no case exceed 1.5 mm.

Weighbeams

3.4.1.12 The scale marks (graduations) must consist of lines of equal thickness. The distance

between graduations should not be less than 2 mm so that the normal machinery tolerances

for notches or scale marks do not cause errors in the weighing results exceeding 0.2 e.

3.4.1.13 Graduation should be perpendicular to the beam.

3.4.1.14 The normal balance position of a weighbeam must be horizontal; the weighbeam must have

equal travel above and below the horizontal. The total travel distance between trig loops and

between other limiting stops near the weighbeam must be sufficient to ensure accurate

reading. The following minimum distances are recommended:

Table 2: Recommended minimum travel distances

Distance from the weighbeam fulcrum to the limiting stops (centimetres)

Minimum travel between the limiting stops (millimetres)

30 or less >30 to 50

>50 to 100 more than 100

10 13 18 23

3.4.1.15 A shoulder or a stop shall be provided on each weighbeam bar to prevent a poise from

traveling and remaining back of the zero graduation.

Poises



3.4.1.16 No part of a poise (including the locking screw) shall be readily detachable. The adjusting

material in a poise must be securely enclosed and firmly fixed in position and must not be in

contact with the weighbeam. There must be no cavity that could accidentally hold foreign

bodies.

3.4.1.17 A sliding poise, other than a hanging poise, on a notched weighbeam bar must have a pawl

that will seat the poise in a definite and correct position in the notches, wherever in the

notch the pawl is placed, and hold it there firmly and without appreciable movement.

3.4.1.18 Sliding poises must be provided with an indicating component. The indicating component of

a poise must be sharply defined and the reading edge shall be parallel to the graduation

lines.

Counterpoise Weights

3.1.4.19 Counterpoise weights shall comply with the requirements prescribed by sections 20, 72, 73,

77, 78 and 79 of the Weights and Measures Regulations.

Revision

Original document


Part: 2 Section: 4 Recorded Representation (Printed)

Reference

Sections 30 to 38, 66 and 67 of the Specifications Relating to Non Automatic Weighing Devices (1998)

4.0 Recorded Representation (Printed) - Generalities

The recording element (printer) of a device shall be appropriate and compatible with the device. Recorded

representations must be clear, definite, accurate and easily readable. The interfacing of a printer to a device

must not cause any alteration or degradation of the metrological characteristics of the device and must not

facilitate the perpetration of fraud. The following are requirements that apply to printers and printed tickets.

4.1 All recorded values shall be permanent, legible and printed in digital format.

4.2 The device must indicate and print weight values in the same unit of measurement.

4.3 The value of d printed and the value of d displayed must be the same (except for postal scales and

weight classifiers).

4.4 The value of d printed may be larger than the value of d displayed by a weight classifier provided

that the measurement, the weight classification and the pricing are accurately determined. Tests

must be performed at the turning points of price ranges.

4.5 Except for weight classifiers, a printer must record the same value and number of decimal places as

indicated on the display.

Clarification: A digital indicator may display weight values in 0.005 kg and 0.01 lb scale

Intervals. The printer must therefore record weight values to 0.005 kg in metric and

0.01 lb when measuring in pounds. It may not record weight values to 0.010 lb.

4.6 All recorded weight values, such as gross, tare, net, inbound and outbound weights, shall be clearly

identified using acceptable words, abbreviations or symbols (see Appendix 2-A). However, if only

one weight is printed, it does not have to be identified as the “net“ weight.



4.7 If the unit of measurement of the device can be externally selected by the user (lb/kg switch), the

printer must record the proper unit of measurement along with the weight values. Preprinted tickets

stating the weight unit are acceptable for indicators capable of displaying one weight unit only or

which have an internal lb/kg switch.

4.8 Computation must be in mathematical agreement (gross weight - tare weight = net weight;

unit price x net weight = total price, rounded off to the nearest cent).

For Price Computing Devices

4.9 Unit prices must be printed when total prices are shown and both have to be clearly identified as the

unit price and the total price.

For Point of sale (POS) weighing systems

Definition: a weighing element or a non computing scale interfaced with an electronic cash register or

computer. Usually, the cash register or computer reads the gross weight provided by the

scale, assigns a tare through a PLU code and prints a net weight on the cash register tape.

The cash register must not interfere with the operation of the scale. A stand alone price

computing scale used in conjunction with an electronic cash register would not fall into this

category.

4.10 The cash register tape must provide the information required by section 67 of the Specifications.

That is, the net weight, the price per unit, the computed price, and the appropriate identification code

or product name. Furthermore, in order to standardize content and layout, as well as adding clarity

to POS receipts, it is recommended that the rules and the example found in the table Point of Sale

(POS) Receipts, at the end of this section be followed. Please note that the identification

code/product name has been left out of the example for clarity; this information is however required

on actual POS receipts.

Note: A POS system may display the gross weight on the scale display and the net weight on the cash

register display; however, it must print the net weight on the cash register tape. The scale of a POS

system is not required to display the net weight nor provide an indication that a tare value has been

entered.



Training mode is no longer required on POS systems. For Weight Classifiers 4.11 In the case of weight classifiers, it is acceptable if the printed ticket provides the weight only or the

weight along with the total price to be paid. The unit price is not necessary since the total price to

be paid is determined on the basis of weight ranges within the device’s weighing capacity rather than

on the basis of a price per unit. Point of sale (POS) receipts 4.12 Printed receipts must comply with the following requirements: Point of Sale (POS) Receipt Requirements

Column Value Requirements

I Measured Quantity Must be identical to the scale display (interval size and capacity limitation). Must print a zero before the decimal point if the weight is less than 1 kg or lb. (e.g. 0.55 kg) A period or comma can be used as the decimal point. (e.g. 1.25 kg or 1,25 kg)

II Measured Quantity Unit of Measure

"kg" or "lb" must be all lowercase letters. The use of "kgs", "lbs" or "#", as the symbol for pounds, are not acceptable.

III Linking Measured Quantity and Unit Price

The symbol "@" or the word "at" or ("à" in French) are all acceptable. Optional if the other values are clearly identifiable in a titled column format

IV Dollar sign for Unit Price

"$" may be placed before or after the value in column V. The symbol is required for unit price.

V Unit Price Must be two digits after the decimal point (e.g. $1.23) Must be preceded by a zero, before the decimal point, if the value is less than one. (e.g. $0.99) A period or comma can be used as the decimal point. (e.g. $1.23 or $1,23)

VI Linking Unit Price and Unit Quantity

The symbol "/" or the word "per" or ("par" in French) are all acceptable. Optional if the other values are clearly identifiable in a titled column format.

VII Unit Price Quantity "kg" or "lb" must be all lowercase letters. The use of "lbs" or "#", as the symbol for pounds, is not acceptable.

VIII Dollar sign for Total Price

"$" may be placed before or after the value in column IX. The symbol is required for total price if there is only one space between columns VII and VIII. Optional in there are two or more spaces.

IX Total Extended Price Must be two digits after the decimal point. (e.g. $1.23) Must be preceded by a zero, before the decimal point, if the value is less than one. (e.g. $0.99) A period or comma can be used as the decimal point. (e.g. $1.23 or $1,23)

* Note: Product identification code/name is also required

Spacing:

- A space is required between columns I and II (due to the use of “lb”)

- At least 1 space is required between columns II and III



- At least 1 space is required between columns III and IV

- No space between columns IV and V, regardless of whether the “$” is placed before or after the

”12.49”

- A space between columns V and VI is optional if the slash “/” is used. If the word ”per“ (“par“ in

French) is used then a space is required

- A space between columns VI and VII is optional if the slash “/” is used. If the word ”per“ (“par“ in

French) is used then a space is required

- At least 1 space is required between columns VII and VIII

- No space between columns VIII and IX, regardless of whether the “$” is placed before or after the

”12.49”



Sample receipts:

Revision

Original document


Part: 2 Section: 5 Values Defined

Reference

Section 35 of the Specifications Relating to Non Automatic Weighing Devices (1998)

5.0 Values Defined - Generalities

Graduations, indications, and recorded values that are intended to have specific values as well as

metrologically significant annunciators must be adequately identified by suitable words, abbreviations or

symbols. These defining terms must be placed relative to graduations, indications, recorded values or

annunciators and as close as practical to them without interfering with their readability. The proper symbols

for SI units are found in Schedule I of the Weights and Measures Act; other acceptable abbreviation or

symbols can be found in Appendix 2-A of this manual.

5.1 Graduations, weight indications must be properly defined by appropriate figures, words or symbols

(lb, kg, ounces, tare, net weight, etc.).

5.2 Annunciators that are metrologically significant are defined with appropriate words or symbols.

Note 1: Only metrologically significant annunciators are required to be identified, namely:

• Unit price display

• Total price display

• Gross, Tare and Net displays and annunciators

• Center of zero annunciator

• lb/kg unit annunciator

• Scale selection annunciator on a multi-platter device

• $ / kg and $ / kg (if applicable)

• Other annunciators required in this Manual

Note 2: The metrological annunciators may be identified using durable labels except when the

annunciator must be capable of changing automatically to reflect a change of status

(Examples: Tare on/off, center of zero yes/no, lb/kg, etc.)

Note 3: The position of the lb/kg toggle switch is not a sufficient indication of the unit in use.

5.3 Gross weight, Tare Weight and Net Weight, Inbound/Outbound Weight, Unit Price, Total Price and

other required information must be adequately identified by names, abbreviations or symbols.


Part: 2 Section: 5 Values Defined

5.4 The names, abbreviations and symbols are suitably located.

5.5 If the device has an external key or switch (user key) to change the measurement unit (lb/kg), the

printer must automatically print the appropriate unit of measurement.

5.6 The external user key or switch of a device must automatically change the measurement units (lb/kg

key) associated with indicated and printed gross weight, tare and net weight.

Note 4: If the device can operate only in a single unit of measurement, it is acceptable that the

symbol or name identifying the unit of measurement is pre-printed on the ticket rather than

printed by the device.

Note 5: If only one weight value is printed, it is assumed that it is the net weight. In such a case,

identifying the weight as to be the net weight is not required.

Revision

Original document


Part: 2 Section: 6 Agreement of Registration

Reference Section 18 of the Specifications Relating to Non Automatic Weighing Devices (1998) Schedule II of the Weights and Measures Act 6.0 Agreement of Registration - Generalities Devices may be calibrated in one unit and use internal calculations to convert from that unit to other units. All indications in different units must be in agreement with each other at all times. Conversion factors can be found in Schedule II of the Weights and Measures Act. LG-6.01 Test for the agreement of registrations Purpose The purpose of this test is to establish the accuracy and reliability of communication among all means of indication and registration of a device. The means of indication and registration include primary and secondary indications, printers, computers and other recording means. Application This test is applicable when a device is equipped with two or more means of registration that register in the same units of measurement (i.e., primary indicator, secondary indicator, printer, etc.). The test applies to mechanical analogue devices and electronic digital indicating devices. If the device (or weight indicator) can be interfaced to a printer, a compatible printer must be attached to the device for the test. The following test must be performed for each unit of measurement that the device can display. Test Procedure 1. Zero the device. 2. Verify the agreement between indications and registrations at zero load (or the minimum load that

can be printed). 3. Apply a load to the load receiving element and print. 4. By 1d steps, increase the load on the load receiving element by 10d, noting the registrations

(including the printouts) at each step. 5. Repeat the test with different loads (e.g., close to zero load, at mid capacity, close to capacity). 6. Verify the agreement of all indications and registrations, including the printouts. Interpretation of Results Weight indications and registrations must agree within the limits prescribed by the Specifications. The device complies with the requirements when the quantities indicated and/or printed are in agreement within the following limits: Electronic digital values having the same value of verification scale interval must be in exact agreement; Analogue values having the same value of verification scale interval must agree within 0.25 times the value of the verification scale interval;



Mechanical digital values, electronic digital values having different verification scale intervals, and combined digital and analogue values must agree within 0.6 times the value of the largest verification scale interval. The agreement of registration requirements are applicable when indications and registrations of weight values are in the same weighing mode (net, gross or tare). Indicated and registered net weights must therefore agree, within the above limits, as must indicated and registered gross weights and indicated and registered tare weights. However, this requirement is not intended to apply when a device indicates a gross weight and prints a net weight, as is the case with some POS systems. The indication of a gross weight and the printing of a net weight is acceptable on POS systems as well as weighing systems used in applications other than direct sales to the public. Weight Classifiers The verification scale interval of a printing device (i.e., printer, computer) may be larger than the verification scale interval of the weight classifier to which it is interfaced. In addition to the "agreement of registration" test described above, a test at the turning points of price ranges is performed to ensure that in all circumstances packages are classified accurately. Example: Weight classifier 10 kg x 5 g The scale interval of the printing device is 10 g Price ranges: 0 - 30 g (Included) = $1.00

Greater than 30 g = $2.00 $ Apply a load so that the weight indication is 25 g. $ Print the weight and price. The ticket may print 20 g or 30 g, and must print $1.00. $ Apply a load so that the weight indication is 30 g. $ Print the weight and price. The printed weight must be 30 g, and the price must be $1.00. A weight of 40 g and a price of $2.00 (second price range) may not be printed before the weight classifier indicates 35 grams. LG-6.02 Suitability of Unit Conversion Purpose To uncover registration errors resulting from an inadequate unit conversion mechanism. This type of error is found when a DUT internally calculates a mass indication in a unit of measurement prior to converting it, rounding it off and registering it in a different unit of measure. Application To all DUT capable of indicating in a metric and in a non-metric unit of registration. Test Procedure

Part 1

1. For each of the units of measurement in which the DUT is capable of registering, perform the two following steps.

2. Set the DUT to register in the unit of measurement being verified.

3. At least fourteen times, add a test load equal to e and each time, record the registration.



Part 2

4. Apply at load and record the indication in the unit the device was calibrated in. Use the

“small weights“ method to determine the true weight as indicated by the device. Remove the ”small weights“ once the true weight has been determined.

5. Set the device to all other units it is capable of displaying and record the indication for

each.

6. Repeat steps 1 and 2 for 3 more loads, spread throughout the range of the device. Interpretation of the Results The DUT is deemed to meet the requirements if: $ Part 1: for each unit of measurement tested, the registration did not skip any steps. $ Part 2: The device accurately converts the weight indication Example of non compliance

Applied load (lb)

Internal metric reading (kg)

Rounded to 0.05 kg (kg)

Conversion to lb (lb)

Indication in lb (lb)

49.6 22.49817769 22.5 49.6040175 49.6 49.7 22.54353692 22.55 49.71424865 49.7 49.8 22.58889615 22.6 49.8244798 49.8 49.9 22.63425538 22.65 49.93471095 49.9 50 22.67961461 22.7 50.0449421 50 50.1 22.72497384 22.7 50.0449421 50 (error) 50.2 22.77033307 22.75 50.15517325 50.2 50.3 22.8156923 22.8 50.2654044 50.3 50.4 22.86105153 22.85 50.37563555 50.4 50.5 22.90641076 22.9 50.4858667 50.5 50.6 22.95176999 22.95 50.59609785 50.6 50.7 22.99712921 23 50.706329 50.7 50.8 23.04248844 23.05 50.81656015 50.8 50.9 23.08784767 23.1 50.9267913 50.9 51 23.1332069 23.15 51.03702245 51 51.1 23.17856613 23.2 51.1472536 51.1 51.2 23.22392536 23.2 51.1472536 51.1 (error) 51.3 23.26928459 23.25 51.25748475 51.3 51.4 23.31464382 23.3 51.3677159 51.4 51.5 23.36000305 23.35 51.47794705 51.5

Note: 1 Under section 39 of the Specifications, indicated and printed representations of net,

gross and tare weights of a device must have the same value of verification interval e for any given load.



Note: 2 In the case of a secondary indicating element intended to duplicate, for the benefit of consumers, the information displayed by the operator's indicating element, the registration on both displays must be in the same graduation size and in the same unit of measurement. Furthermore, the printed registration intended for the consumers must be exactly as the indicated registration (e.g. same graduation size and same unit of measurement).

Note: 3 An indicating element and a printer used in conjunction must at least register in the same

unit of measurement. Supplementary information in other units of measurement may be provided by the indicator and/or printer.

Note: 4 A device may display weight values in two units of measurement simultaneously. Note: 5 All weight indications and registrations must be within tolerances. Note: 6 Devices may transmit incomplete data (i.e. weight values without units) for non-

metrological purposes such as monitoring, inventory, etc. Revision Rev. 1 (March 2010)

• Added second part to LG-6.02 to test for accuracy of conversion • Formatting change


Part: 2 Section: 7 Price Computing Feature

Reference

Sections 19, 30 to 35, 46 and 47of the Specifications Relating to Non Automatic Weighing Devices (1998)

7.0 Price Computing Feature - Generalities

Devices used for direct sale can incorporate some cash register functionality, such as computing a

total price for goods based on its weight and a pre determined unit price. All three of these values

must always be in mathematical agreement with one another. In addition various requirements are

described below to ensure clarity for all parties and to prevent the facilitation of fraud.

7.1 Price computing devices must print the unit price when the total price is printed.

7.2 Displayed and recorded monetary values must comply with applicable requirements of section 3,

Indication and Registration Representation, and of section 5, Values Defined in this Guide (e.g.

Value of d, legible and readable, number of digits, decimal representation, defining words and

symbols, etc.).

7.3 Devices intended for direct sale to the public:

7.3.1 Devices must display the unit price when the total price is displayed.

7.3.2 When the device displays in kilograms, the unit price that can be entered and displayed is

limited to price/100 g and price/kg.

7.3.3 When the device displays in Canadian units, the unit price that can be entered and

displayed is limited to Price/lb.

7.3.4 When a device displays weight values on the basis of the gram or ounce, unit prices may

also be entered and displayed on the same basis.

Note: Devices capable of having their PLUs programmed in units other than metric and Candian must have

the access to this functionality restricted by a password at minimum.



7.4 A weighing system must not display or record any values when the correct calculated values exceed

the display or printing capability. (An entry of 8 digits made into a defined field length of 7 digits will

give an error indication).

Clarification: If a unit price of $99.99/kg and a weight of 10.050 kg may be entered, then the

total price display must have enough digits to display the extended price

$1 004.90 (at least 6 digits).

7.5 The total price must be calculated accurately and rounded to the nearest one cent, by multiplication

of weight and unit price, both as indicated by the device. Perform the test described in LG-7.02

7.6 When the displayed weight is less than zero, the device must not be capable of displaying or printing

a computed total price. Place a small load on the platter, tare it and remove it from the platter. A

negative weight value should be displayed. Attempt to enter a unit price. Attempt to print this value.

7.7 When the scale indicates an overcapacity condition, the device must not be capable of displaying or

printing a weight and/or computed total price.

7.8 The displayed weight and total price must be free floating, that is when the scale displays a unit

price, a weight and a total price, if the weight or the unit price is changed the total price must

change accordingly.

LG-7.01 Free Floating Signal

Purpose

To ensure that the displayed net weight and total price are free floating. That is when the scale displays a

unit price, a weight and a total price, if the weight or the unit price is changed, the total price must change

accordingly. All applicable tests are to be performed.

Procedure for Price Computing Scales

• Place a load on the platter.



• Enter a unit price; a total price is now displayed. Ensure that the indicated monetary value is in

mathematical agreement with the weight and unit price to the nearest cent.

• Increase the load on the platter; the total price must increase accordingly. Procedure for Scales Equipped with a Tare Display

• Enter a Keyboard or a platter tare value.

• Place a load greater then the value of the tare; the scale displays a gross weight, a tare weight and

a net weight.

• Ensure that the gross, tare and net values are in exact mathematical agreement.

• Change the tare value; the net weight should change accordingly. Procedure for POS systems - Against a Price Lookup Code (PLU)

• Determine the keying sequence necessary to cause the device to compute a final price using a

preprogrammed price lookup code (PLU).

• Place a load on the platter

• Key in the complete sequence except the last keystroke required for price computation.

• Change the load on the platter.

• Operate the final keystroke to initiate price computation. Procedure for POS Systems - Against a Manually Scaled Item

• Determine the keying sequence necessary to cause the device to read the scale, allow the operator

to enter a price per unit ($/kg) and if applicable a department code, and then compute a final price.

• Place a load on the platter

• Key in the complete sequence except the last keystroke required for price computation.

• Change the load on the platter.

• Operate the final keystroke to initiate price computation. Interpretation of Results 7.9 The device complies with the requirements if:

• in all circumstances, mathematical concordance is maintained; and



• in the case of a POS system, it computes total prices using the load on the scale at the

time the final key was pushed, or produce an error signal, or lock out to prevent any price

computation.

LG-7.02 Agreement of Registration of Monetary Values

Purpose

To determine if the scale computes accurately and rounds the values of total prices correctly.

Application

Applicable to any price computing scales and POS systems.

Test Procedure

• Apply several loads to the scale and enter different prices.

• With a calculator determine the correct values, round them off to the appropriate decimal, and

compare them to the total price indicated by the scale.

• The following are suggested loads and unit prices:

Table 1: Suggested test loads and unit prices

Test # Net Weight (kg) Unit Price Total Price Correct

Indication

A 0.01 $4.54 $0.045 40 $0.05 B 0.01 $4.55 $0.045 50 $0.05 C 0.01 $4.90 $0.049 00 $0.05 D 0.01 $5.10 $0.051 00 $0.05 E 0.01 $2.50 $0.025 00 $0.02 or $0.03 F 0.01 $2.51 $0.025 10 $0.03 G 0.651 $0.76 $0.494 76 $0.49 H 0.652 $0.76 $0.495 52 $0.50

• Apply the following rounding rule:

Table 2: Rounding rules examples

Computed Results Correct Indication



0.020 0.021 0.022 0.023 0.024

0.025 0 0.025 1

0.02 0.02 0.02 0.02 0.02

0.02 or 0.03 0.03

Interpretation of Results The monetary registration is correct if for a net weight (as outlined in the "Net Weight" column in the above

table) and a unit price (as outlined in the "Unit Price" column in the above table) yields the corresponding

indication (as outlined in the "Correct Indication" column in the above table). Revision Original document


Part: 2 Section: 8 Recorded Representation of Gross, Tare and Net Weights

Reference

Section 19, 30, 31, 32 and 33 of the Specifications Relating to Non Automatic Weighing Devices (1998)

8.0 Recorded Representation of Gross, Tare and Net Weights - Generalities

There are two primary requirements concerning the printing of weight values. First the recorded values must

be mathematically correct and, second, the recorded values must be in agreement with the displayed values.

Two situations provide the greatest potential for non compliance with these requirements. One is when a

platter tare is taken to the internal resolution of the scale and the scale indicates and records gross, tare and

net weights. In the second, a scale sums the analog signal from two or more weighing elements and the

scale indicates and records gross, tare and net weights.

LG-8.01 Agreement of Registration of Gross, Tare and Net Weights

Application

The following procedure is performed on an electronic scale when a tare is taken to the internal resolution

and the scale can display and/or print gross, tare and net weights.

• Place a load on the platter that results in a scale indication that is just below the zone of uncertainty

(or upper edge of the interval) and press the push-button tare key.

• Add more weight to the scale so the gross load is just above the zone of uncertainty (lower edge of

the scale interval).

• Compare the indicated and recorded values for the gross, tare and net weights. Values must be in

mathematical agreement; indicated and printed values must be in agreement.

Table 1: Example of possible non compliance on a 50 t x 10 kg scale

Load perceived by the scale to the internal resolution Displayed and Recorded Values

45 006 kg Gross 45 010 kg Gross


Part: 2 Section: 8 Recorded Representation of Gross, Tare and Net Weights

20 004 kg Tare 20 000 kg Tare

25 002 kg Net 25 000 kg Net

Application

The following procedure is performed on an electronic scale that sums the analog signals from two or more

weighing elements and the scale displays and prints gross, tare and net weights.

• Place a load on each weighing element that results in a weight indication just below the zone of

uncertainty (upper edge of the scale interval), or just above the zone of uncertainty (lower edge of

the scale interval).

• Compare the indicated and recorded values for the gross, tare and net weights. Values must be in

mathematical agreement; indicated and printed values must be in agreement.

Table2: Examples of possible non compliance on a 300 kg x 0.1 kg scale

Load to internal

resolution Displayed values

Load to internal

resolution Displayed values

Scale 1 25.04 kg 25.0 kg 25.06 kg 25.1 kg

Scale 2 25.04 kg 25.0 kg 25.06 kg 25.1 kg

Sum 50.08 kg 50.1 kg 50.12 kg 50.1 kg


8.1 The device complies with the requirements if the displayed and printed values of gross, tare and net

weights are in mathematical agreement (N + T = G); and displayed values agree with printed

values.

Revision

Original document


Part: 2 Section: 9 Manual Weight Entries

Reference

Sections 30, 31, 32, 33 and 38 of the Specifications Relating to Non Automatic Weighing Devices (1998)

9.0 Manual Weight Entries - Generalities

Note: This section does not apply to keyboard tare entries (see section 17.0 for tare requirements).

Metrological features of a device used in trade must be of such design, composition and construction so as

to ensure accurate measurement and minimize the potential for fraudulent use. Many devices incorporate

features that allow the operator to enter a weight value through a numeric keypad or keyboard. This weight

value can be displayed and/or printed with no load on the load receiving element.

Manual weight entries may be necessary in certain circumstances, such as POS systems, when credit must

be given, or when generating labels for standard packages or correcting erroneous tickets. However, this

capability may increase the potential for fraudulent device use if it is permitted without suitable precautions.

Manual weight entries can therefore be allowed under the following conditions:

9.1 The device must be incapable of weighing when it is processing or printing a manual weight entry.

9.2 Displayed and printed manual weight entries must be adequately defined and must be automatically

identified as "Manual Weight", "Manual WT" or "MAN WT" (“poids manuel”, “pds manuel“ or

“PDS MAN”).

Clarification 1 When a manual weight entry is printed and automatically identified as such,

displaying the manual weight value is optional. If, however, the manual weight

value is displayed, it must be properly identified as such.

Clarification 2 Identification of a manual weight entry, with the proper term, must be done

automatically without the need for operator intervention.


Part: 2 Section: 9 Manual Weight Entries

Clarification 3 The use of a symbol to identify multiple manual weight entries is permitted provided

that the symbol is defined on the same page as that on which the manual weight

entries appear and the definition of the symbol is automatically printed by the

recording element as part of the document.

Clarification 4 The following symbols are not acceptable: MAN, MW

9.3 Manual weight entries must be an optional feature that can be enabled/disabled and sealed against

use in applications where their use is inappropriate and could facilitate fraud.

Exceptions In the case of an Unattended Vehicle System, Manual Weight entries may be made while

the scale is not at zero (truck remaining on scale) where communications has been lost

between the scale and the system computer.

[In Service, Field Test - CFTM/GSC 2002-04]

Revision

Rev. 1 (March 2010)

Requirement for entry only at gross load zero revoked


Part: 2 Section: 10 Indicating Zero and Negative Values

Reference Sections 30 to 33, and 41 of the Specifications Relating to Non Automatic Weighing Devices (1998) 10.0 Indicating Zero and Negative Values - Generalities The purpose of the following requirements is: to ensure that devices can be set and maintained as close as possible to a true zero value; to eliminate possible confusion between under and over indicated weight values; and to ensure that the smallest value of scale interval for digital devices remains an adequate representation of device accuracy. Indicating Zero 10.1 The device must be provided with means to adequately indicate or record a "zero-balance"

condition. 10.2 Automatic indicating devices must provide an out-of-balance indication on both sides of zero.

Clarification 1 Over/Under Indicators: At least one graduation on each side of the zero reference must be provided. Clear indication must be provided to differentiate between the below zero and above zero portions of the chart. Clarification 2 Digital: The minimum acceptable indication of a zero balance condition must be one of the following: a) if a decimal point or comma is used, at least one digit to the left and all digits to the right

of the decimal point must be displayed; b) if a decimal point or comma is not used, at least one active decade plus any constant

(fixed) zeros must be displayed; c) all decades to the right of a decimal point must be active, i.e. a fixed zero cannot appear

to the right of a decimal point. Table 1: Examples of displaying zero

Max x d (kg)

Minimum Zero Indication

25 x 0.01 0.00 5 000 x 1 0 50 000 x 10 001 1. The last digit may be fixed.

In the case of an electronic digital display, the zero balance indication may be a continuous digital weight indication or be indicated by other means provided that the scale either automatically inhibits the scale operation or returns to a digital weight indication when an out-of-zero balance condition exists (See section on sleep mode).

10.3.1 A digital indicating scale must either automatically maintain a "center-of-zero" condition to ± ¼ e or

less (AZT) or have a center-of-zero indicator that defines the zero balance condition to ± ¼ e or less. Class I or II devices with auxiliary indicating means must define a zero balance condition to ± ½ d only. Therefore, these devices are not required to have a center-of-zero annunciator or an AZT. Perform test LG-15.01.



10.3.2 If the zeroing range of AZT is less than the width of zero (± 0.4 d ), then a center of zero indication

that defines the zero balance condition to ± ¼ d or less is required. Otherwise the scale could possibly display zero and not be truly set to zero within ± ¼ d. In this case, the operator would not be warned that the device needs to be re-zeroed. Perform test LG-15.02.

10.4 If provided, the center-of-zero indicator must be inhibited at all displayed weight values other than

zero ± ¼ e (or ½ d for class I or II devices with auxiliary reading means). Clarification: The centre-of-zero light may only be on at net load zero, or at gross load zero if no

tare is entered. (Policy on centre of zero light when can the center of zero light be on.wpd) 10.5 On digital indicating devices, a + or - sign must not appear when the scale is indicating zero in any

of the available units. Displaying Negative Values 10.6 A display of negative value is required in the net display mode when the gross weight is less than

the tare value. 10.7 A negative value must be indicated in a manner that cannot be confused with a positive weight

value. A minus sign clearly associated with the weight indication may be used provided that it is located in a manner that does not interfere with the weight.

10.8 Blanking the display is a method that may also be used to indicate an under-zero condition when

the device is in the gross mode (no tare); the scale may also display symbols which cannot be interpreted as a quantity value (e.g. EEEEEE, UNDERLOAD, S-1, etc.). A row of zeros, flashing zeros or flashing weight values are not acceptable means.

Note 1: For devices such as hopper or tank scales, it is recommended to indicate a negative

balance condition and an over-capacity condition differently so that the load condition is evident for the operator.

Note 2: For devices such as hopper or tank scales, if blanking the indication is used, it is also

recommended that the indicator has an annunciator to indicate "power on" so the operator does not think that the power has been lost when the display is blank.

Sleep Mode or Displaying Non Metrological Information Definition: The term ”Sleep Mode“ used in this section means a function of a device that blanks partially or totally indications after a defined period of non use, in order to save the screen or to display information other than weights; it also refers to the shut off condition of a device following a period of non use. Also known as ”power save mode“ or ”economy mode”. A device may go in a sleep mode or may display non metrological information such as advertisement, greetings, time and date, etc. provided that the following conditions are met: 10.9 The scale totally or partially blanks its indications or displays non metrological information only

when the device is at gross load zero (no tare) and has reached a zero-balance condition. 10.10 If the device blanks its indications partially only or displays non metrological information, the

displayed information cannot be construed as weight indications.



10.11 The scale must be provided with an automatic means to inhibit the weighing operation or return

the device to a continuous digital indication when the scale is in an out-of-balance condition. Perform the test described in LG-10.01.

10.12 Printing function must be inhibited when the device is in sleep mode. Alternative A scale may go into "sleep mode" with a load on the platter, if the scale is designed to prevent any further weighing operation before the load is removed from the platter, all tares are cancelled and the device is reset to zero. In this case the device must bear a special legend "The scale is set to zero when in the sleep mode" (or similar message) adjacent to the weight display for the customers' view. LG-10.01 Means of Automatically Restoring Weight Indication Application This test will be performed on any electronic device with a sleep mode or capable of displaying non metrological messages. Purpose To ensure that the device has means of detecting when it is no longer in a zero-balance condition and restoring a weight indication; and also to ensure that the printing function is inhibited when in sleep mode. Test Procedure

7. Ensure that the "sleep mode" function is activated; 8. Zero the device and wait until the device goes to the "sleep mode" or display non metrological

messages; 9. In one firm motion (so as to prevent the AZSM from capturing part of the test load) apply a load

equal to e. The non-zero/non-metrological registration must have been replaced by a mass registration equal to e;

10. Wait 5 minutes (or the normal delay for the device to return to the sleep mode) to see if the device

will go into a "sleep" mode with a load on the platter; 11. Zero the device with the load on the platter and wait until the device goes to "sleep mode" or

display non metrological messages; 12. Attempt to print; 13. In one firm motion, remove the 1 e test load. The device must display a mass of - e, or provide an

under-weight indication. Interpretation of Results The device complies with the requirements if:

• it does not go into a "sleep" mode when there is a load on the platter; • it returns to a weight indication when an off-zero condition exists; and • the printing function is inhibited.



• The device meets the requirements also if, in the case it goes to Asleep@ mode with a load on the platter, it prevents any further weighing before the load is removed, tare is cancelled and the device is re-zeroed.

Revision Rev. 1 (March 2010) - AZSM renamed to AZT - Formatting changes


Part: 2 Section: 11 Load Receiving/Weighing Element

Reference


11.0 Load Receiving/Weighing Element - Generalities

Scales used to weigh wet commodities such as fish, lobster, etc. are required to have a load-receiving

element, generally a scoop or platform with raised edges, to effectively drain off liquid that would tend to

accumulate on the scale. This requirement does not apply to small computing scales such as those used in

supermarkets since few wet commodities are weighed. In those particular applications, the scoop or platter

can be easily removed and cleaned to maintain the zero balance condition.

11.1 If the load receiving element is designed to receive wet commodities, it must also be designed to

drain effectively.

11.2 Tank or hopper scales and their associated piping or conduit must be designed to ensure proper

drainage and complete delivery of products.

Scales must be designed such that the normal movement of load receiving elements (platform, pan, etc.)

during use will not "bind" and interfere with the weighing operation. This is checked by shifting the load

receiving element when loaded. Mechanical systems must be designed to reduce frictions.

11.3 The load receiving/weighing element is designed to remain centrally aligned under load; lateral

movements of the platter or platform do not cause bindings or frictions that interfere with the

weighing operations.

If a device has a locking feature, this feature must only have two stable positions corresponding to "lock"

and "weigh" (no intermediate position), and weighing must only be possible in the "weigh" position.

Electronic digital devices must "blank" and inhibit printing in the "locked" position.

11.4 The device locking feature (if any) has only two positions: "locked" and "weigh".

11.5 Weighing is possible only in the "weigh" position, and the locking feature does not interfere in any

way with the weighing operation.


Part: 2 Section: 11 Load Receiving/Weighing Element

11.6 Overload protection (stoppers) must be set so that they do not interfere with weighing operation.

Revision

Original document


Part: 2 Section: 12 Load Cell - Relationship of Vmin and d

12.0 Load Cell - Relationship of Vmin and d - Generalities

No requirements for the time being.

Revision

Original document


Part: 2 Section: 13 Damping Means and Up-Dating of Weight/Price Data

Reference


13.0 Damping Means and Up-Dating of Weight/Price Data - Generalities

The weight indications must stabilize shortly after a load is applied to the scale. Weight indications must not

oscillate significantly or update so slowly that intermediate weight values are misinterpreted as the final stable

weight value. Weight indications, unit and total computed sale prices, after the weight indication is stable and

after introduction of unit price, must remain visible while the load is on the platter to allow proper reading of

the values.

Acceptable Solutions

• On a mechanical device, damping should achieve a stable indication after three to five half periods

of oscillation.

• (OIML criteria) For digital electronic devices, after a change in load sufficient to overcome the

sensitivity threshold of the device, the previous indication should not persist for longer than 1

second.

• (OIML criteria) On a price computing scale, indication of weight, unit price and total price should

remain visible for at least 1 second after the weight indication is stable and after introduction of a unit

price while the load is on the platter.

• (OIML criteria) After the removal of the load, the indications may remain visible for no more than 3

seconds provided that the indication has been stable before and the indication should otherwise be

zero. As long as there is a weight indication after removal of the load, it must not be possible to

enter or change a unit price. Computed prices may remain visible while the platter is empty

provided that this does not lead to confusion, measurement errors or fraud.

13.1 The mechanical device is equipped with an effective means for damping oscillations.

13.2 The electronic device up-dates the displayed weight information at a sufficient rate to prevent

misinterpretation of the final weight value.

13.3 Indications of weight, and if applicable unit and total prices, are visible and stable when the load is

on the platter.


Part: 2 Section: 13 Damping Means and Up-Dating of Weight/Price Data

13.4 A digital computing scale may continue to display computed price information following removal of the

load provided that:

13.4.1 it does not display computed price information for more than 15 seconds (hold period);

13.4.2 it returns immediately to its zero weight reference;

13.4.3 it must automatically return to a "non-hold" or active mode at any time a new unit price is

entered or the next load is placed on the platter;

13.4.4 it must return to an active mode and print the correct weight and price information for the

current load conditions if it initiates label printing or a "print command" is given during the

"hold" period.

Revision

Original document



Reference Sections 30 to 33 and 40 of the Specifications Relating to Non Automatic Weighing Devices (1998) 14.0 Limits of Indication - Generalities Weighing devices shall neither indicate nor print weight values in excess of their maximum rated capacities (Max). Perform the following test. LG-14.01 Overload Tests Application Applicable to complete electronic weighing devices and to separate electronic weight indicators. If the units of registration can be changed without having to perform a re-calibration of the device, then perform individual tests for each and every unit which the device is capable of registering. Note: For the purposes of the Display Blanking Test, a POS (Point of Sale System) is considered a

computing scale and is subject to a maximum of 9 d. Test Procedure Span

1. Stabilize and zero the device at nominal conditions. 2. Load the device to its maximum rated capacity. 3. Add loads until the device ceases to display weight values. 4. Record the last weight value indicated (WI); attempt to print or transmit data to external ports at

overload condition.

Note: On some devices, under overload conditions, data is not transmitted through the printer port; however, it may be transmitted through another port.

5. Repeat the test for other units of measurement that the device can display.

WI ≤ Max + (5% Max or 9 e)

Tare Features

1. Remove the load and set the device to zero. 2. Enter a keyboard or a platter tare (T) equal to approximately 20% of Max. 3. Add loads until the device ceases to indicate/print weight values. 4. Record the last value indicated (WI).

WI + T ≤ Max + (5% Max or 9 e)

Note: Certain approved devices may incorporate a full or partial additive tare feature. An additive tare

feature extends the weighing capacity of the scale. This must be taken into consideration when performing the blanking display test.



Zero (To be performed if the scale can zero loads in excess of 4%) Positive Portion

1. Remove the load and set the device to zero. 2. Add a load equal to 4% of Max; zero that load using the SAZSM. 3. Apply any load the can be re-zeroed using the AZSM and re-zero the load. Record this value as

(ZI) 4. Add loads until the device ceases to display/ print weight values; Record the last value indicated

(WI). 5. If the scale limits the amount that can be zeroed with a semi-automatic zero setting mechanism

but the operation can be repeated several times, zero the maximum weight possible equal to or under 5% of Max.

WI + Zl ≤ Max + (5% Max or 9 e)

Negative Portion

1. Place a small weight that is within both IZSM and SAZSM range of the device, on the platter and re-zero the device using the IZSM (device must have an IZSM to continue with test)

2. Once the scale has reached a zero condition remove the small weight and re-zero the device using the SAZSM.

3. Add loads until the device ceases to display/ print weight values; Record the last value indicated (WI)

WI ≤ Max + (5% Max or 9 e)

Interpretation of Results 14.1 The device is deemed to comply with the requirement if the device can not display or print weight

values in excess of:

• 9 scale divisions, for computing scales other than weight classifiers and postal scales or;

• 105% of Max, for other scales. 14.2 When over capacity, the device registration must blank within prescribed limits, or display a clear

message that cannot be confounded with a weight value. Acceptable Solutions Amongst others, the following means of indicating overcapacity are acceptable:

• a row of "EEEEEEE" • a blank registration • the word "OVERCAPACITY"

Among others, the following means of indicating overcapacity are not acceptable:

• displaying a flashing eights • displaying a row of zeros or eights

The same rules apply to printed information.



Revision Rev.1 (March 2010) • Test for zeroing a negative quantity included • Altered procedure for devices that can zero over 4%


Part: 2 Section: 15 Zero Setting Mechanisms

Reference Sections 30 to 33, 40, 41, 42, 43 and 44 of the Specifications Relating to Non Automatic Weighing Devices (1998) 15.0 Zero Setting Mechanisms - Generalities There are several requirements that establish the proper operation of zero setting mechanisms to ensure accuracy and to prevent the perpetration of fraud or inadvertent measurement errors. These requirements depend upon the type of zero setting mechanisms and applications. Definitions Manual Zero-Setting Mechanism (MZSM): mechanism for setting the indication to zero by the operator (balance ball or potentiometer). Semi Automatic Zero-Setting Mechanism (SAZSM): mechanism for setting the indication to zero automatically following a manual command (Push-button Zero). Automatic Zero Tracking (AZT): mechanism for maintaining the zero indication within certain limits, automatically. Initial Zero Setting Mechanism (IZSM): mechanism for setting the indication to zero automatically at the time the device is switched on and before it is ready to use. Automatic Zero-Setting Mechanism (AZSM): mechanism for automatically returning the device to a zero condition from a negative indication. 15.1 Manual Zero-Setting Mechanism (MZSM) 15.1.1 If the balance at zero-load is achieved by the addition of supplementary material, the material

must be enclosed in a cavity covered with a screw cap (or a cover with screws, etc.) so that it cannot be readily removed or altered and so that it cannot shift position in such a way that the balance condition of the device is affected during weighing operation.

15.1.2 If a device is provided with a balance ball and a captive screw or nut arrangement, the maximum

effect must not exceed 4 verification intervals per revolution, and means must be provided to ensure sufficient friction to prevent a zero change during weighing operation.

15.1.3 A device intended for direct sales to the public may not be fitted with a MZSM unless operated

only with a detachable tool. 15.1.4 The total range of zero setting (positive and negative portion) may not exceed 4% of the device

capacity unless the gross load that can be weighed is not increased beyond the device capacity limit. Perform the test described in LG-15.03.

15.2 Semi Automatic Zero-Setting Mechanism (SAZSM) 15.2.1 SAZSM must operate only when the scale provide a stable indication (See section 18.0, Motion Detection, test LG-18.01).



15.2.2 SAZSM (Push Button Zero) must set the indication to only zero, within ± ¼ e. The SAZSM of a Class I or II device equipped with an auxiliary reading means must set the indication to zero to ± ½ d. Perform the test described in LG-15.01.

15.2.3 The activation of SAZSM must not clear stored tare weight values. Enter a platter or keyboard

tare and attempt to clear it by pressing the zero button when the platter is empty (zero or negative indication) and loaded (positive weight indication).

15.2.4 The total zero-setting range (negative + positive) must not exceed 4% of the device capacity. The

range may exceed 4% of Max provided that the gross load that can be weighed is not increased beyond the capacity limits of the device. Perform the test described in LG-15.03.

15.2.5 Devices that use alternate triggers for the SAZSM (such as lifting the platter) should function

appropriately and not facilitate fraud. 15.3 Automatic Zero Tracking (AZT) 15.3.1 The device AZT must not re-zero (in one shot) a weight value in excess of 0.6 e. Perform the test

described in LG-15.02. 15.3.2 The total zero-setting range (negative + positive) must not exceed 4% of the device capacity. The

range may exceed 4% of Max provided that the gross load that can be weighed is not increased beyond the capacity limits of the device. Perform the test described in LG-15.03.

15.4 Initial Zero Setting Mechanism (IZSM) 15.4.1 The IZSM must set the device to zero within ± ¼ e. The IZSM of a Class I or II device equipped

with an auxiliary reading means must set the indication to zero ± ½ d. Perform the test described in LG-15.01.

15.4.2 Determine if the value that can be "zeroed" by the device IZSM exceeds 20%. Perform the test

described in LG-15.04. Record this value. Clarification This information is needed to establish which procedure will be followed for certain

performance tests. If the IZSM range does not exceed 20%, the performance tests are done once with the maximum dead load. If the range exceeds 20%, certain performance tests are performed twice: one with the minimum dead load, the second with the maximum dead load. Individual procedures described in Part III indicate to which value IZSM must be set.

15.4.3 The IZSM range of indicators tested and approved separately must not exceed 20%. 15.5 Automatic Zero Setting Mechanism (AZSM) 15.5.1 The AZSM must set the device to zero within ± ¼ e. The AZSM of a Class I or II device equipped

with an auxiliary reading means must set the indication to zero ± ½ d. Perform the test described in LG-15.01.

15.5.2 AZSM must only operate when the weight display is below zero. 15.5.3 AZSM must only operate when the device is in Gross mode. 15.5.4 There must be a means to enable/disable the AZSM and it must be sealable



15.5.5 The indication must be stable for at least 5 seconds before this function activates. Perform the

test described in LG-15.05 Summary of Zero Setting Mechanisms Ranges and Accuracy Requirements

Zero Setting Mechanism (ZSM) Type

Limit type MZSM AZT SAZSM AZSM IZSM Accuracy see 15.1.2 None ± ¼ e

±½e for Class I, II1

± ¼ e ±½e for Class I, II1

± ¼ e ±½ e for Class I, II1

Total Zero Setting Range 4% 4%2 4%2 4%2 20%3 LG-15.01 Center-of-zero indication and setting zero within ± 1/4 e Application Applicable to complete electronic scales and separate electronic indicators having SAZSM or IZSM or equipped with a "center-of-zero" indicator. Purpose This test is to verify that the SAZSM and IZSM automatically set the device to zero within ± ¼ e, and to verify that the device range of center-of-zero indication is equal to or less than ± ¼ e. Note that the range of center-of-zero indication of Class I or II devices equipped with auxiliary reading means is ± ½ d. This must be taken into consideration when performing the following tests and interpreting the results. Take into account that the ZU of weight classifiers is adjacent to the graduation. Procedure Setting zero to within ± ¼ e.

1) Switch the AZSM and AZT off or set its value to zero effect; zero the DUT. 2) Place a load of at least e (comprised of 10 * 0.1e weights) on the platter and RE-ZERO the device. 3) Successively remove small denomination weights in 0.1e steps until the low end of the interval is

reached (the indication begins to alternate between 0 and -1 e). Record the weights removed as being the negative portion of the interval.

4) Successively add small denomination weights in 0.1e steps until the high end of the interval is reached (the indication begins to alternate between 0 and +1 e). Record the value of the weights added and subtract the value of the weights recorded in the preceding step. The difference is the positive portion of the interval.

5) Determine if the zero position as set by the SAZSM does not deviate from the true zero reference point by more than ¼ e. Generally, the zero position, as automatically set by the SAZSM, should coincide with the zero reference point; in such a case, the negative range would equal the positive range. See illustration.

6) Repeat the test by zeroing the device using the IZSM. Width of the Centre-of-zero Indication (Annunciator)

1) Switch the AZSM and AZT off or set its value to ZERO effect. 2) Set the device to zero. 3) Place a load of at least e (comprised of 10 × 0.1 e weights) on the platter; zero the DUT.



4) Successively remove small denomination weights in 0.1 e steps until the visual confirmation of zero goes off. Record the value of the weights removed as being the negative portion of the center of zero indication.

5) Successively add small denomination weights in 0.1 e steps until the center-of-zero indicator goes off (positive limit). Record the difference between the value of the weights remaining on the platter and the value of the weight recorded in the preceding step as being the positive portion of the center-of-zero indication.

Interpretation of Results The DUT is deemed to comply with the requirements if the zero setting mechanisms automatically set the device to zero within ± ¼ e from the true zero reference point, and if the centre-of-zero annunciator indicate a zero balance condition within ± ¼ e of the true zero reference point. Note: For Class I or II devices with auxiliary reading means, the range is ± 0.5 d. LG-15.02 AZT - Maximum Incremental Load that can be Zeroed. Purpose To determine that the largest load that can be deposited at one time on the device, while the DUT is at zero load, is equal to or less than 0.6 e. Procedure Check for the addition of small loads:

1) Ensure that the AZT is on and the AZSM is disabled; Zero the device. 2) Place a known test load "A" equal to or greater than e (e.g. 10 e), plus a load "B" equal to 0.7 e on

the device load receiving element. 3) Remove known test load "A", wait at least 10 seconds to see if the device will automatically re-

zero test load "B". 4) If the device did not zero test load "B", repeat with smaller test loads (0.6 e, 0.5 e, 0.4 e, etc) to

determine the maximum positive AZT range. Record the maximum value that the AZT will re-zero. Check for the removal of small loads:

1) Disable the AZSM (if applicable) 2) Place a small known test load "A" equal to or greater than e (e.g. 10 e), plus a load "B" equal to

0.7 e on the load receiving element. 3) Re-zero the device. 4) Remove all loads. A negative value ("A" + "B") should now be displayed. 5) Place the test load "A" back on the device and wait 10 seconds. The device should not reset to

zero. 6) If the device resets to zero, repeat with smaller test loads "B" (0.6 e, 0.5 e, 0.4 e, etc) to determine

the maximum negative AZT range. Record the value. Interpretation of Results The device is deemed to comply with the requirement:



• (First test) if after the removal of test load A, the device does not re-zero automatically with the load equal to 0.7 e left on the load receiving element (it is allowed to re-zero automatically when there is a load equal to or less than 0.6 e); and

• (Second test) if after the addition of load A, the device does not re-zero automatically when the load is 0.7 e behind zero (it is allowed to re-zero automatically when there is an apparent negative load equal to or less than 0.6 e).

Clarification The software of the device may allow the AZT range to be set to different values

(0.1e, 0.2e, 0.5e, 0.6e, 1e, 3e, etc.). Technologists must ensure that the AZT can be set at a value that is within the maximum permissible value, and sealed.

LG-15.03 Re-Zero Range (Maximum total range of SAZSM/AZSM/AZT/MZSM) Application Applicable to complete electronic scales, electronic indicators, and mechanical scales equipped with balance ball type of zero setting. Purpose This test is used to determine whether the total range of the zero setting mechanism, other than the initial zero setting mechanism (IZSM), exceeds 4%; and if the total range exceeds 4%, to ensure that the gross load that can be weighed is not increased beyond the capacity limit of the device. The procedure depends upon the type of zero setting mechanism. On mechanical devices, the procedure is relatively simple. Procedure for Mechanical Devices (beam scales, dial scales, etc.)

1) Place a load (8-10 % of Max) on the load receiving element. 2) Set the balance ball to the lowest setting (low end of the range) and note the indication. 3) Set the balance ball to the highest setting (high end of the range) and record the indication.

Interpretation of Results The difference between the indications at the low and high ends must not exceed 4% of Max. Procedure for Electronic Digital Devices On electronic devices, the SAZSM, AZT and AZSM setting ranges must be determined. As illustrated below, in some scale designs, there is only one common parameter that limits the range over which the SAZSM, AZT and the AZSM can function. When so designed, it is relatively easy to determine the total range because one only has to find the SAZSM range using weights and then to confirm that the AZSM and AZT have also been disabled once the limits of the range have been reached. For this type of design, use the "Weight method". In other scale designs, there are two distinct range limiting parameters; one for the SAZSM and one for the AZT. It is then necessary to find the limits of the SAZSM range and then to find the limits of the AZT range. The total range is then a sum of the two.



Procedure - "Weight method" Determination of the negative portion of SAZSM/AZSM/AZT

1) Place on the LRE a load approximately equal to 6% of Max. This load should be made up of several smaller weights allowing for the gradual withdrawal of the load.

2) Activate the Initial Zero Setting Mechanism by switching the DUT "OFF" and "ON" (Note: on some devices, it may be necessary to unplug and reconnect the power cord in order to activate the IZSM). The DUT should then have zeroed the 6% load and display a zero registration.

3) By successively removing loads and activating the SAZSM (i.e. zero button), determine to the nearest d the maximum load that can be removed from the LRE while still allowing the DUT to perform a semi-automatic zeroing. Record this value.

4) Once the DUT no longer performs a semi-automatic zeroing (The scale is just below the low range of SAZSM), remove a load equal to 0.5e; wait 1 minute. Remove an additional 0.5e and wait 1 minute. If the DUT's AZSM or AZT has not re-zeroed the 1e (0.5e + 0.5e) (and thus the DUT is displaying a -1e registration), this will have confirmed that the SAZSM, AZT and AZSM share the same range limit in the negative direction. Record this value.

5) If the AZSM, AZT and SAZSM do not share the same range continue removing loads until the AZSM no longer functions, or all weight has been removed. Record the value of all the weights removed.

6) Once the DUT no longer performs automatic zeroing (The scale is just below the low range of AZSM), remove a load equal to 0.5e; wait 10 seconds. Remove an additional 0.5e and wait 10 seconds. If the DUT's AZT has not re-zeroed the 1e (0.5e + 0.5e) (and thus the DUT is displaying a -1e registration), this will have confirmed that the AZT and AZSM share the same range limit in the negative direction.

7) Record the total amount of weights removed as being the negative portion of the Total Range of SAZSM/AZSM/AZT.

Note: If the DUT's AZT has re-zeroed the 0.5 e load that was removed, and if the DUT appears to continue automatically zeroing additional 0.5 e loads upon removal, then the "Water Method" will be used to determine the AZT range.

8) Restore all weights removed (thus restoring the 6% of Max on the LRE) and re-zero using the

SAZSM. (The DUT should now be indicating a zero registration). Determination of the positive portion of SAZSM/AZT

1) By successively adding loads and activating the SAZSM (i.e. zero button), determine to the nearest e the maximum amount of load that can be added to the LRE while still allowing the DUT to perform a semi-automatic zeroing.

2) Once the DUT no longer performs a semi-automatic zeroing, add an additional load equal to 0.5 e; wait few seconds. Add an additional load of 0.5 e. If the DUT's AZSM has not re-zeroed the 1e (0.5 e + 0.5 e) (and thus the DUT is displaying a +1 e registration) this will have confirmed that the SAZSM and AZSM both share the same range limit in the positive direction. Record the total amount of weights added as being the positive portion of the Total Range of SAZSM/AZT.

Note: If the DUT's AZSM has re-zeroed the 0.5 e load that was added, and if it the DUT appears to continue automatically zeroing additional 0.5 e loads upon removal, then the "Water Method" will be used to determine the AZSM range.

3) The sum of the positive and negative portion is the total range of SAZSM/AZSM. If the sum

exceed 4% of Max, proceed with the test LG-14.01.



Interpretation of Results If the total SAZSM/AZSM/AZT range(s) exceed 4% of the device capacity, the device is deemed to have complied with the requirement if the gross load that can be weighed is not increased beyond the capacity limit of the device. Example 15 kg x 0.005 kg computing scale Step 1 0.600 kg (4%) placed on the scale; scale is zeroed. The scale indicates zero. Step 2 An additional 5 kg is placed on the scale. The scale is zeroed. Step 3 Load the scale until it indicates an overload condition. The maximum value that may be indicated

is 10.045 kg (15 kg - 5 kg + 9d). LG-15.04 IZSM Range (Maximum Range of Initial Zero Setting Mechanism) Application This test is applicable to electronic indicators and to complete electronic devices. Purpose The purpose of this test is to determine whether or not the total range of the initial zero setting mechanism exceeds 20%. The initial zero setting mechanism is the mechanism that sets the scale to zero upon power up. Clarification - Electronic indicators tested and approved separately The load receiving element to which an electronic indicator tested and approved separately will be interfaced will not have been tested up to 200% of Max. Consequently, the maximum Initial Zero Setting Mechanism range of electronic indicators must be limited to 20% of Max. Procedure for Electronic Indicators Note: The following explanation of the test procedure is based upon the use of a load receiving element

connected to the electronic indicator because it is easier to explain the procedure this way. However, the actual test can be performed using a load cell simulator or a rheostat provided that the basic principles are maintained. The procedure consists of calibrating the electronic indicator so that it only uses a small portion of the total capacity of the LRE.

1) Connect the indicator to a LRE and calibrate the indicator so that it is at a zero balance condition

when the LRE is loaded at 50% of its maximum capacity and that it displays the number of intervals "n" (as requested by the applicant) when the LRE is fully loaded (Cap).

2) By trial and error, find the negative (-ve) portion of the electronic indicator's IZSM range by removing a load(s) from the LRE and by trying to zero it using the electronic indicator's IZSM. The IZSM is triggered by unplugging and replugging the power cord (Note: on some devices, it is sufficient to switch it off and on).

3) Similarly, by trial and error, find the positive (+ve) portion of the electronic indicator's IZSM range by adding a load(s) to the LRE and by trying to zero it using the electronic indicator's IZSM.

Procedure for Complete Electronic Scales Note: Whenever possible, perform the procedure described above for electronic indicators tested

separately; or:



1) Remove the platter in order to reach the lowest point of the IZSM range. 2) By trial and error, find the positive (+ve) portion of the electronic indicator's IZSM range by adding

a load(s) to the LRE and by trying to zero it using the electronic indicator's IZSM. The IZSM is triggered by unplugging and replugging the power cord (Note: on some devices, it is sufficient to switch it off and on).

Interpretation of Results An electronic indicator tested and approved separately is deemed to comply with the requirements when the total range of the Initial Zero Setting Mechanism (absolute value of negative (-ve) portion of the range plus the positive (+ve) portion of the range) does not exceed 20% (or can be set to a maximum of 20% and sealed) of the DUT's maximum capacity (Max); The IZSM range of a complete electronic device may exceed 20% of Max if the device performs within tolerances when the IZSM is set at the minimum and maximum points of its range. When the IZSM range is limited to 20%, performance tests are conducted once: at the maximum IZSM setting. When the IZSM range exceeds 20%, certain performance tests are conducted twice: at the minimum and at the maximum setting of the range. See description of the performance tests in Part 3. LG-15.05 AZSM - Maximum Load that can be Re-zeroed Application Applicable to complete electronic scales and electronic indicators Purpose This test is used to determine whether the range of the automatic zero setting mechanism exceeds 4% and does not activate for at least 5 seconds after the indication is stable. Procedure Both the range and time limit of the AZSM must be determined. The AZSM may only re-zero negative quantities.

1) Place a load (5% of Max) made up of small weights on the load receiving element. 2) Activate the IZSM 3) Remove all weight from the platter (device should now indicate -5%, give an error, or blank) 4) Allow device to stabilize and wait at least 5 seconds (or the time indicated by manufacturer for

activation of the AZSM). If the device re-zeroes the load then record the value of the weights removed and the time required for activation of the AZSM. If not, continue with the test

5) Successively add small loads, waiting at least 5 seconds (or the time indicated by manufacturer for activation of the AZSM) to see if the AZSM activates. Continue adding weights until the AZSM range of the device is determined. Record this value and the time required for activation of the AZSM

Interpretation of Results The device should not re-zero a negative load greater than 4% of the device capacity and may only re-zero after the indication has been stable for at least 5 seconds. If a load greater than 4% was re-zeroed complete LG-14.01.



Revision Rev. 1 (March 2010)

• AZSM renamed to AZT • added new definitions for AZT and AZSM • added requirements and test for new AZSM function (LG-15.05) • removed Method 3 from LG-15.03 and altered procedure to reflect new AZSM/AZT • table outlining all zeroing functions added

Rev. 2 (May 2013)

• Removed method 2 from LG-15.03


Part: 2 Section: 16 On-Board Weighing Systems

Reference Sections 3, 21 and 31 of the Specifications Relating to Non Automatic Weighing Devices (1998) 16.0 On-Board Weighing Systems - Generalities The following requirements apply only to on-board weighing systems. 16.1 On-board weighing systems are restricted to Class III, IIIHD and IIII 16.2 e must be less than or equal to 5 g for Class III on-board weighing systems 16.3 equipped with a means to blank the weight indications and prevent the transmission, printing and

storage of the weight results when the registrations are no longer within the applicable limits of error.

16.4 Neither gross values nor tare values shall be entered manually in on-board weighing systems. Revision Original document


Part: 2 Section: 17 Tare

Reference Section 31 of the Specifications Relating to Non Automatic Weighing Devices (1998) 17.0 Tare - Generalities Tare features must be designed and used to ensure accurate measurement and prevent the perpetration of fraud. There are numerous requirements that establish the proper operation of tare features depending upon the type of devices, the type of tare capability and the intended use of the device. The extent of the requirements depends upon the application. For instance, design and operation requirements for devices used in direct sales to the public are more stringent than those applicable to devices used in other applications. In general, and unless otherwise specified for particular types of tare, devices must provide a clear indication for both the operator and the consumer that a tare value has been entered; platter and keyboard tare values must be visible at some point during the weighing process and the alteration of platter or keyboard tare values, during the weighing process, must be impossible without being noticed. On the other hand, devices that are used in industrial applications or in other applications where the consumer is not normally present, need only provide the operator with a clear indication that a tare value has been entered and have a means to display the tare value on demand. Definitions Additive Tare means a tare entry that does not affect the device weighing capacity. A keyboard

or platter tare entry of 10 kg on a 15 kg capacity scale that has an additive tare feature will still leave the possibility of weighing a net load of 15 kg.

Auto-tare means an automatic platter tare. With the scale indication at zero, the scale

automatically tares, within a pre-determined range, the value of the first load (container) put on the platter. The net weight of the commodity is then determined.

Keyboard tare means a fixed or percentage tare value entered through the keyboard (e.g. 20 g,

1.3%, etc.) or through one of the selectable tare keys to which tare values are assigned.

Percentage tare means a tare value, expressed as a percentage (e.g. 5.6 %), that represents the

percentage of tare material compared to the gross weight of the commodity. A percentage tare is one form of proportional tare.

Platter tare means a tare entry achieved by placing an object (e.g. a container, bag, etc.) on

the platter and pressing the tare key. The device then indicates zero as the net weight with the object on the platter.

Preprogrammed tare means a tare value that has been entered, retained in the device memory and

assigned to a PLU code or product name. It can be a fixed tare value and/or a proportional tare value.

Proportional tare means a tare value, automatically calculated by the scale, proportional to the

gross weight indicated by the scale. A proportional tare can be a percentage tare or a fixed tare value proportional to a range of gross weights (i.e., a 10 g tare for gross weights between 0 and 2 kg, a 20 g tare for gross weights between 2 and 4 kg, etc.). A proportional tare is, therefore, not limited to being a percentage tare.



17.1 Applicable to any type of scale or weighing system and to any type of tare 17.1.1 The tare mechanism must only operate in the backward direction (under-registration). Perform the

test described in LG-17.01. 17.1.2 The device must ignore or reject the entry of a zero tare value. The entry of a zero tare (or a 0%

proportional tare) must not activate the "tare entered" or "net" annunciator nor cause the display to automatically switch to the net display mode. (Scales with a continuous tare display or tare display mode will indicate zero when the tare entry is zero. However, the entry of a zero tare must not cause the display to automatically switch to the net mode).

17.1.3 The tare value must be equal to the value of the displayed scale division for all methods of tare

entry (dtare = d). An attempt to enter a tare value that is not equal to Ad@ must be rejected or rounded off to the nearest scale interval (see Section 22 for specific requirements pertaining to multi-interval and multiple range devices).

17.1.4 The tare weight signal must be "free floating". If the tare value is changed during the weighing

operation, the net weight must be re-adjusted accordingly (net + tare = gross). 17.1.5 The sum of the tare value entered or preprogrammed and the net weight that can be weighed

must not exceed the gross weight capability of the device (Max + 9 e for computing scales and POS systems; Max + 5% for other scales). See overload test in Section 14.

This does not preclude a device from having a full capacity tare plus a full capacity weighing range (additive tare). In such a case, tests for accuracy, repeatability, eccentricity, etc. must be performed based on the maximum weighing capacity with the maximum tare value entered.

17.1.6 It shall not be possible to enter a value of tare that exceeds the tare capability range (e.g., a tare

entry of 6 kg on a scale with a tare range of 5 kg must be rejected and not taken as 5 kg). 17.1.7 Whenever net, gross and tare weights are indicated or printed, they must be in exact

mathematical agreement (net + tare = gross) and the total price must be calculated on the basis of the net weight.

17.1.8 The use of any mechanism to select the unit of measure (lb/kg switch) must be inhibited when a

tare is entered (through the keyboard, platter or preprogrammed) unless all weight values, including the tare value, are automatically converted and accurately rounded off to the nearest scale interval.

17.1.9 If a device is designed to automatically clear the tare after each weighing, it must also be

designed to prevent the automatic clearing of a tare before a stable weight indication has been provided and the transaction completed.

Clarification: On a price computing scale, the transaction is only completed with the entry of a unit price

and the computation of the total price. The removal of the commodity from the platter before the total price is computed must not automatically cancel the tare.

17.2 Platter and keyboard tare 17.2.1 Pressing the tare button once, or several times, with a load on the platter (platter tare) must set

the device to zero and only to zero.



17.2.2 Except for POS systems, the device must provide a visual confirmation or indication that a platter

or keyboard tare has been entered (see the particular requirements for preprogrammed tares and POS systems).

Acceptable means of providing visual confirmation:

• The device has a separate and continuous tare display. • The device displays simultaneously or in sequence (within a time interval of a few

seconds), for the operator and the consumer, the gross, tare and net weights with their proper descriptors.

• The device displays the net weight only, with an annunciator (net legend) near the weight display. Gross weight is displayed when the tare weight is zero and the net legend or annunciator is off.

• A legend, annunciator (tare entered) or similar statement is used to indicate that a tare value has been entered and the display indicates the net weight.

• The device has selectable gross and net weight display modes with proper descriptors. • It is recommended that video display terminals that are the primary indicators of devices

simultaneously display the gross and tare weights when the net weight value has been determined.

Note: Appropriate annunciators or descriptors must go "on" when tares are entered; not "off". 17.2.3 The entry of a platter or keyboard tare must automatically override any previous tare entry or be

rejected (i.e., they cannot be additive). A percentage tare value may however be entered in addition to a fixed keyboard or platter tare value.

17.2.4 Unless a separate tare display is provided, the device must display a negative weight value when

the weight of the load on the platter is smaller than the tare weight. 17.3 Preprogrammed tare (fixed or percentage) 17.3.1 Preprogrammed tare values may only be assigned (programmed) when the device is at gross

load zero and in a "configuration" mode. 17.3.2 Fixed and/or percentage tares may be preprogrammed into PLU codes. PLU codes may be

entered or changed at any time, whether or not a load is on the platter. 17.3.3 Except for POS systems, scales must display the net weight ("net" legend on) when a

preprogrammed tare is entered through a PLU code.

25.55 kg GROSS

NET

25.55 kg NET

25.55 kg

5.00 kg

20.55 kg

GROSS

TARE

NET



17.4 Percentage tare 17.4.1 Fixed and percentage tares may be added to obtain a total tare value for a transaction. For

instance, a PLU code may be preprogrammed with cumulative fixed and percentage tares; or a fixed platter or keyboard tare may be entered first, and then, through a PLU code, a percentage tare applied.

17.4.2 If a device can sum fixed and percentage tare values, the two values must be added first and then

the total tare value rounded off to the nearest scale interval. There is therefore no benefit in expressing percentage tare values with more than one decimal place (e.g. 1.5 %, 3.3 %, etc.).

Examples Scale: 15 kg x 5 g

Total gross weight TGW

Fixed tare

weight FTW

Gross weight GW = TGW-FTW

Percentage tare value

%T

Percentage tare weight calculated GW x %T


Total tare (fixed + percentage) Net

weight NW

Calculated Rounded

355 g 10 g 345 g 9.2% 31.74 g 355 g 41.74 g 40 g 315 g

Scale: Multi-interval, 0-2 kg x 1 g, 2-5 kg x 5 g


Fixed tare

weight FTW

Gross weight GW = TGW-FTW

Percentage tare value

%T

Percentage tare weight calculated GW x %T


Total tare (fixed + percentage) Net

weight NW

Calculated Rounded

2890 g 9 g 2881 g 11.2% 322.672 g 2890 g 331.672 g 330 g1 2560 g 332 g2 2558 g3

17.4.3 The visual confirmation that a tare has been applied (i.e., “net” annunciator) must only be enabled

if the percentage tare multiplied by the gross weight represents one or more scale intervals after the appropriate rounding. The turning on of the “net” annunciator must only occur if the net weight does not equal the gross weight (i.e., a tare has actually been applied to the gross weight).

Note: These acronyms are used in the following equations:

%T (Percentage tare) TW (Tare Weight) GW (Gross Weight) NW (Net Weight) TGW (Total Gross Weight) FTW (Fixed Tare Weight) The %T of a commodity is determined as follows:

100% ×=GWTWT



NW is determined as follows: ( )[ ]FTWTGWTFTWTGWNW −×−−= % or

( ) ( )TFTWTGWNW %1−×−= 17.5 Devices used for direct sale to the public 17.5.1 Except for preprogrammed tare, proportional tare and POS systems, when keyboard or platter

tare values are entered the scale must comply with one of the following requirements:

17.5.1.1 the tare value is permanently indicated on a separate dedicated display; or 17.5.1.2 the tare value is indicated as a negative value when there is no load on the load receiving

element; 17.5.2 A platter or keyboard tare value may not be entered, modified or cancelled unless the device is at

gross load zero or the device indicates a negative weight value. This does not apply when the tare is continuously indicated on a separate dedicated display (or, as a minimum, the new tare value is clearly displayed to the customer at some point during the transaction) nor to a preprogrammed tare associated with a PLU.

Example A platter or keyboard tare value is entered on a computing scale and a negative

value is indicated. If the wrong tare value was entered, it may be cancelled and replaced by a new tare value when the platter is empty. This new tare value will be indicated as a negative weight value. However, the correction must not be possible with a commodity resting on the platter (positive weight indication). In such instances, the operator must remove the commodity from the platter and then cancel or change the tare value.

Clarification The zero indication/no load condition does not apply to a preprogrammed tare

value. The idea being that the operator should not be capable of altering a tare value without providing the consumer with an indication that a new tare value has been entered. In the case of a preprogrammed tare associated with a PLU code, the tare value is rarely displayed. However, it is unlikely that the operator will select the wrong PLU code or product name, or change the PLU code during the weighing operation, to reduce the tare value. Such actions would affect the unit price and would be detectable by the consumer.

17.5.3 Platter or keyboard tare values may be retained between transactions. 17.5.4 Auto-tares are prohibited in direct sale to the public applications. 17.6 Devices intended for industrial applications or other applications where consumers are not

normally present 17.6.1 A tare may be cancelled or modified while a load is on the load receiving element provided that

the device has means to indicate, on demand, the value of the tare. These means include a negative weight value displayed when the platter is empty or a means to recall the tare value. A clear indication must be provided to the operator that a tare has been entered or cancelled (a tare annunciator is sufficient).

17.6.2 Tare values may be retained between transactions. 17.6.3 Combined semi-automatic zero/tare buttons are permitted under the following conditions:



17.6.3.1 The requirements of Section 15.2 for semi automatic zero setting mechanisms must be met. Namely the zero/tare mechanism operates only when the scale provides a stable indication; the mechanism sets the indication to zero, only, within ± ¼ e (or ½ d for Class I and II devices equipped with auxiliary reading means); the zero range does not exceed 4% of scale capacity unless the gross load that can be weighed is not increased beyond scale capacity.

17.6.3.2 The scale is intended to be used exclusively for industrial applications or applications

where consumers are not normally present.

17.6.3.3 The AZSM or Center-of-Zero annunciator must be effective when the device displays zero after a zero setting operation (within the zero range). The AZSM may also work when zero is indicated after a tare operation. See Section 10.3.

17.6.3.4 The AZSM operates as prescribed in Section 15.3. Namely, the AZSM does not re-zero

weight values in excess of 0.6 e; the total AZSM range does not exceed 4% of scale capacity unless the gross load that can be weighed is not increased beyond scale capacity.

17.6.3.5 The scale must be permanently marked, near the weight display(s), with the legend "Not

for Use in Direct Sale to the Public" or similar language and the ranges of both zero and tare operation (e.g. zero range up to 7d - tare range above 7d).

17.6.3.6 The range of zero and tare operation must not be user selectable (i.e. fixed or, as a

minimum, a sealable parameter).

17.6.3.7 Visibility of operation - the scale is required to display an indication (“net” annunciator) that a tare has been entered when a weight value within the tare range is subtracted by activating the zero/tare button.

17.7 Point of sale systems Definition a weighing element or a non computing scale interfaced with an electronic cash register

or computer. Usually, the cash register or computer reads the gross weight provided by the scale, assigns a tare through a PLU code and prints a net weight on the cash register tape. The cash register must not interfere with the operation of the scale. A stand alone price computing scale used in conjunction with an electronic cash register would not fall into this category.

17.7.1 A POS system may display the gross weight on the scale display; however, it must print the net

weight on the cash register tape. The scale of a POS system is not required to display the net weight nor provide an indication that a tare value has been entered.

17.8 Multi-interval and multiple range scales

See Section 22.0 of this manual. 17.9 Customers' scoreboard

See Section 23.0 of this manual.



LG-17.01 Tare - Backward Direction Purpose The following test is to ensure that a weight value (positive tare) cannot be added to the weight of a load being weighed. Application Applicable to complete electronic scales and electronic indicators equipped with a tare function. Test Procedure - Push Button Tare

• Zero the DUT • Place a weight in excess of the AZSM range on the load receiving element, and re-zero the scale. • Activate the tare mechanism (Push Button Tare), the scale should indicate zero. • Remove the weight; this should result in a negative indication. • Attempt to take this value as tare using the push-button tare capability. The negative number

should not be taken as a tare. Test Procedure - Key-Board Tare, Programmable Tare • Attempt to enter or pre-program a positive tare through the Key-board. Interpretation of Results The DUT is deemed to comply with the requirement, if a "positive" value cannot be entered or programmed as a tare value. Revision Original document


Part: 2 Section: 18 Motion Detection

Reference

Sections 30, 31, 32 and 45 of the Specifications Relating to Non Automatic Weighing Devices (1998)

18.0 Motion Detection - Generalities

Electronic devices must have motion detection capability to prevent the device from zeroing (semi-automatic

zero) or taring (platter tare or keyboard tare) a part of the load when the semi-automatic zero or tare key is

activated while a load is added, changed or removed from the platter.

Electronic devices equipped with a printer (or that have connections for a printer) must have motion detection

capability to prevent the device from printing values before the weight display has stabilized. This reduces

the possibility of recording incorrect weight values.

The following test procedure is used to assess the effectiveness of the motion detection feature.

LG-18.01 Motion Detection Test

Application

Applicable to complete electronic scales, or to electronic indicators which are intended to be used as part of

a non-automatic weighing electronic scale (tested by means of a load cell\dead load tester assembly or by

means of a load cell simulator).

Purpose

To determine if printing, zeroing or the entry of a tare is inhibited when motion is detected.

To evaluate the maximum range within which printing is possible in spite of motion.

Procedure

• Place a load within the weighing range on the platter and allow time for the indication to stabilize.

• Induce a motion to the scale indications to a peak magnitude of at least 10 e (amplitude).


Part: 2 Section: 18 Motion Detection

• While disturbing the weight indication, activate the SAZSM and allow the oscillations to settle out.

The scale may eventually zero the load or may reject the command.

• While disturbing the load, attempt to activate the tare button (platter tare). The scale may eventually

tare the load on the platter, or reject the command.

• While disturbing the load, attempt to print. The scale may print a weight or reject the command.

• Repeat the test at least five times for small loads (near zero) and loads near capacity.

Note: For larger capacity devices, it may not be convenient or practical to disturb the load by hand. A

load of greater than 10 e may be applied or removed while activating the zero, tare, stored weight or

print key. Under laboratory conditions, since this is primarily an instrument test, a low capacity load

cell or a load cell simulator may be connected to the device or the indicating element to simulate

motion.


The device complies with the requirements if zeroing, taring or printing the load on the platter is prevented, or

is within 1 e (verification scale interval) for scales that have a maximum capacity of up to

2 000 kg (5 000 lb); or 3 e (verification scale intervals) for scales of more than 2 000 kg (5 000 lb).

Printed and displayed weight values must be within the prescribed limits of error.

18.1 Push-button zero complies with the motion detection requirements

18.2 Push-button (platter) tare complies with motion detection requirements.

18.3 Stored weight key(s) comply with the motion detection requirements.

18.4 Printed weight values comply with motion detection requirements.

18.5 Printed values are within prescribed tolerances.

Revision

Original document


Part: 2 Section: 19 Tilting (Off-level Effect)

Reference Section 21 of the Specifications Relating to Non Automatic Weighing Devices 19.0 Tilting (Off-level Effect) - Generalities Under section 21 of the Specifications, portable or movable devices, other than of the freely suspended type, must perform within tolerances when tilted up to 3°, in any direction. If they can perform within tolerances only when leveled, they must be equipped with permanent and sensitive level indicating means (usually a bubble level). Vehicle mounted weighing devices such as onboard weighing systems for NH3, onboard weighing systems for waste collection, and scales mounted on lift trucks must be able to provide an accurate weight reading up to at least 3°. 19.1 Portable or movable devices Complete scales or load receiving elements other than onboard weighing devices must meet one of the following conditions: 19.1.1 The device weighs within prescribed tolerances, when off level by up to 3°; or 19.1.2 The device is equipped with a permanently installed level indicator as standard feature. Note: If the device is not equipped with a suitable level indicator, perform the tests described in LG-3.04

of Part III, Performance Tests. If the device has a level indicating means, the following requirements must be met:

19.1.2.1 The level indicating means must be permanently and rigidly mounted on a permanent section of the scale. It must be located so as to be easily read. It must be protected from damage and must be sufficiently sensitive.

19.1.2.2 The level indicating means must be readily observable without disassembly that

requires the use of tools. Clarifications

• On small portable devices, the level indicating means may be placed under the platter (if the platter can be lifted easily) or at the back of the scale (if it can be readily observed).

• A bubble level placed under the platform of a movable floor scale is not acceptable if the platform

is relatively heavy and requires tools or assistance to be lift up in order to access the level indicator.

• The level indicating means must be permanently attached to a permanent part of the scale (e.g. it

is not sufficient to attach it to the platter if the patter is removable).

19.1.2.3 The level indicating means must be sufficiently sensitive. Perform the test described in LG-3.05, Part III, Performance Tests.


Part: 2 Section: 19 Tilting (Off-level Effect)

19.2 Onboard weighing systems Definition a weighing device designed as an integral part of or attached to or secured to the frame,

chassis, lifting mechanism or the bed of mobile equipment such as a vehicle, trailer, tractor, or forklift.

19.2.1 The device provides a weight indication up to 3° in any upright direction. 19.2.2 The device weighs within tolerances when off level by the largest of

• 3° ; or • maximum inclination at which a weight indication is still provided.

19.2.3 The weight indication blanks when the inclination is such that the device ceases to weigh

accurately. 19.2.4 Scales mounted on lift trucks (or similar vehicles) must blank their indications when the lift truck is

moving, unless the scale can provide an accurate weight indication. Perform an accuracy (in-motion) test using different loads within the capacity range of the device. The test must simulate actual conditions of use.

Note: See the complete test procedure LG-3.04, Part 3, Performance Tests. Revision Original document


Part: 2 Section: 20 Segment Verification

20.0 Segment Verification - Generalities It is recommended that electronic devices incorporate a test system for verifying all relevant signs of the indicator in their active and non-active state sufficiently long to be checked by the operator. Clarification

• The relevant signs of an indicator are those that are metrologically significant: digits for gross, net and tare weights; + or - signs; tare or net annunciator; centre of zero light; etc.

• The following means of verifying signs are acceptable:

o Test sequence initiated by pressing a special button o Test sequence initiated by pressing key or a sequence of keys o Test sequence initiated by turning the scale off and on

This is not a requirement Revision Original document


Part: 2 Section: 21 Multiple Deck Weighing Systems

Reference


21.0 Multiple Deck Weighing Systems - Generalities

An indicator and/or printer may be connected to more than one weighing element provided that the weighing

system is designed to ensure accuracy of the transactions, and to prevent erroneous measurements or fraud.

Two basic Multiple Deck Weighing Systems are used in trade:

• a system where only one weighing element can be selected and use at a time; and

• a system where all the weighing elements can operate simultaneously. Each weighing element may

have its own indicating element; all indicating elements being connected to a summing weight

indicator. Or the weighing elements are connected to a specially designed multi-deck indicating

element that can display simultaneous or alternating weight values from the individual weighing

elements, and can display the sum of the weights. This second type of Multiple Deck Weighing

system is normally used to weigh vehicles.

21.1 Systems where only one weighing element can be selected and use at a time (Multiplex).

Each separate weighing element and the indicating element is considered a separate scale and must be

tested accordingly.

21.1.1 The system or scale must prohibit the use of any weighing element that is not in use (only one

weighing element at a time).

21.1.2 The indicating element must automatically provide a clear and continuous indication of which load-

receiving element is in use (i.e. Scale A, Scale B, Scale C, etc.). The indication must be visible

from the operator's normal position.

21.1.3 Weighing elements must be clearly and permanently identified with the corresponding identification.



21.1.4 The printer must provide on the ticket, for each weighing, a clear registration indicating which

weighing element was used (Scale A, Scale B, etc.).

21.1.5 When an operator-activated function (Setting zero, entering a tare value, selecting or clearing a

function, etc.) is performed on one particular weighing element, functions or parameters of other

weighing elements must not be affected or altered. Perform the test described in LG-21.01

21.1.6 Unless the indicator has independent AZSMs, one for each individual weighing element, individual

Centre-of-Zero indicators (annunciators), one for each weighing element, must be provided. Centre-

of-Zero indicators must provide a continuous signal (remain active) regardless of which weighing

element is selected.

Note: It is preferable to identify scale weighing elements as scale A, scale B, etc. rather than scale 1, scale

2. Numbers that could be confused with weight indications is not acceptable.

21.2 Systems where all the weighing elements can operate simultaneously (Vehicle scales, vehicle axle

weighing scales); each weighing element has its own dedicated display that are interfaced to a

summing display.

21.2.1 Each weight indicator must be clearly and permanently identified with the corresponding identification

(i.e. Scale A, Scale B, Total weight, etc.). Each weight display and its associated weighing element

is considered a separate scale and must meet all applicable requirements.

21.2.2 When an operator-activated function (Setting zero, entering a tare value, selecting or clearing a

function, etc.) is performed on one particular weighing element, functions or parameters of other

weighing elements must not be affected. Perform the test described in LG-21.01

21.2.3 Unless the indicator has independent AZSMs, one for each individual weighing element, individual

Centre-of-Zero indicators (annunciator), one for each weighing element, must be provided. Centre-

of-Zero indicators must provide a continuous signal (remain active) regardless of which weighing

element is selected.

21.2.4 Each weighing element must be clearly and permanently identified with the corresponding

identification (i.e. Scale A, Scale B, etc.).



21.1.5 The printer must automatically register the printed weight associated with the weighing element

identification that was used (i.e. Scale A, scale B, etc)

21.2.6 The value of verification scale interval must be the same for all displays including the summing

display.

21.2.7 The summing weight display must perform within tolerances; must not indicate nor record nor print

any weight values when one individual weighing element exceeds its capacity; must sum any tare

entries in the individual indicators; must have a free floating weight signal for summing individual

indicators; and must be in mathematical agreement with the sum of all the individual indicators.

Clarification: The device may still display values for individual weighing elements that are not over-

capacity (Policy for blanking of displays of multiple LRE hooked together.wpd)

LG-21.01 Alteration of settings or data entries

Purpose

The purpose of this test is to ensure that when a setting is performed or a function is activated on one

particular weighing element, functions or settings of the other weighing elements are not changed or altered.

Application

Applicable to any Multiple Deck Weighing Systems or indicator intended for Multiple Deck Weighing Systems

Test Procedure

• Zero each individual weighing element.

• Place a small load (i.e. 5 e) on one of the load weighing element; zero that weighing element; verify

if zero balance condition of the other weighing elements have changed.

• Enter a platter or key board tare for each selection of weighing elements in each weighing; clear or

change the tare value on one weighing element; verify if tare values of the weighing elements have

been altered.



• Place different combination of loads on the weighing elements; ensure that the weight are correctly

and accurately indicated; ensure that the printed weights agree with indicated weights and are

properly identified.

• If applicable, ensure that the summing weight display perform within tolerances; does not indicate nor

record any weight values when one individual weighing element exceeds its capacity; sums any tare

entries in the individual indicators; has a free floating weight signal for summing individual indicators;

and is in mathematical agreement with the sum of all the individual weight displays.


The device complies with the requirements if functions performed on individual weighing element do not affect

the settings or entries of other weighing elements; if the indicated and printed weights are accurate and

identified as required; and if the summing weight display meets the requirements (last bullet above).

Revision

Original document


Part: 2 Section: 22 Multi-interval Devices and Multiple Range Devices

Reference

Sections 3, 5, 6, 8, 9, 16, 31 to 33 of the Specifications Relating Non Automatic Weighing Devices (1998)

22.0 Multi-interval Devices and Multiple Range Devices - Generalities

This section provides additional guidelines for the examination and testing of multi-interval and

multiple range devices.

Note: a weight indicator tested separately will be set and tested for a maximum number of intervals (nmax)

and for a minimum value of verification scale interval (emin) across the range.

22.1 Multi-interval devices

Definition Multi-interval device means a device having one weighing range which is divided into partial

weighing ranges each with different scale intervals, with the weighing range determined

automatically according to the load applied (pre-determined ranges/intervals), both on

increasing and decreasing loads.

Intervals and Capacities

22.1.1 On a multi-interval device, the value of the verification scale interval of a particular range must be

lower than the value of the verification scale interval of the next range (e1 < e2 < e3, etc.)

22.1.2 Each partial range of a multi-interval device must have the same value of scale interval for both

increasing and decreasing loads. The verification scale interval e must equal the scale interval d.

22.1.3 Each partial range of a multi-interval device must have the number of scale intervals (n) required by

Section 3 of the Non Automatic Weighing Devices Specifications.

Example Each range of a Class III device must have a minimum of 500 n and a maximum of 10 000

n. The number of scale intervals "n" for each weighing range is determined by dividing the

scale capacity for each range by the verification scale interval "e" for each range. See the

following illustration:



Table 1: Multi-interval example

Partial Weighing Range (Capacity) e n Max / e

0-3 kg 1 g 3 000 3 000/1 3-6 kg 2 g 3 000 6 000/2

6-15 kg 5 g 3 000 15 000/5 Example of a device that would not satisfy the above section 22.1.3

Weighing ranges e n

First 0 - 1 kg 1 g 1 000 Second 1 - 5 kg 5 g 1 000 Third 5 - 8 kg 20 g 400

Example of a device that satisfies section 22.1.3

Weighing ranges e n

First 0 - 1 kg 1 g 1 000

Second 1 - 5 kg 2 g 2 500

Third 5 - 8 kg 5 g 1 600

22.1.4 It is recommended (OIML requirements) that the maximum capacity of a partial weighing range of a

multi-interval device (except the last range) must satisfy the requirements of the following table:

OIML recommended partial range minimums

Class I II III IIII

Maxi/ei+1 ≥ 50 000 ≥ 5 000 ≥ 500 ≥ 50

Tare Features

22.1.5 The maximum tare value that may be entered shall not exceed Max 1.

22.1.6 Whenever gross and tare weights fall in different weighing ranges, the net weight must always be in

mathematical agreement with the gross and tare weights that are displayed and recorded

(simultaneously or in sequence) (gross = tare + net).




entry (dtare = d). An attempt to enter, in the first range of a multi-interval scale, a tare value that is

not equal to d must be rejected or rounded off to the nearest scale interval.

Example A multi-interval scale has a 2 g interval in the first range and 5 g in the second range. A

keyboard entry of 5 g in the first range must be either rounded to 4 or 6 g or rejected.

22.1.8 Weight values (Net or Gross) must always begin with the lowest weighing range on the device

regardless of the amount of keyboard or platter tare that is taken. Example: a multi-interval scale

has two ranges: first 0-2 kg by 2 g, and second 2-5 kg by 5 g. A platter tare of 1 kg is taken; the

device indicates zero. Then, the device must indicate the net weight from 0 up to 2 kg in intervals

of 2 g; and from 2 up to 4 kg, in intervals of 5 g.

22.1.9 When Gross, Tare and Net weights are indicated or printed, there shall be mathematical agreement

in all circumstances. The tare value must be rounded off to permit mathematical agreement.

Example: A multi-interval device has two ranges. The first range 0-2 kg by 2 g, and the second 2-5

by 5 g. A key board tare of 1.998 kg is entered (in 2 g divisions); a gross load of 2.115 (in 5 g

divisions) is put on the platter. The net weight indicated must be either 0.116 kg or 0.118 kg (first

range; rounded off to 2 g division). If the gross, net and tare weights are indicated, they must be

as follows:

Accpetable 1.998 kg tare value rounding examples

Gross Tare Net

Option 1 2.115 kg 1.999

kg

0.116

kg

Option 2 2.115 kg 1.997

kg

0.118

kg

22.1.10 A tare value entered in the lower range may be either rounded off to the nearest value of the

interval of the higher range in which the weighing occurs, or kept unchanged. In the latter case, the

net weight could possibly be displayed with an interval smaller than the interval of the range in which

the weighing occurs. When a device displays or prints the gross, net and tare values, in all cases

the mathematical equation "tare + net weight = gross weight" must be satisfied.



Example A multi-interval scale has a 2 g interval from 0 to 2 kg, and 5 g from 2 kg to 10 kg. A tare

of 12 g is entered in the first range and the gross weight is 2 500 g (second range). The

scale may display either 2 488 g (tare stored as 12 g) or 2 490 g (rounded off to 10 g).

Note: OIML: tare must be rounded off R76-1, section 4.7.1)

U.S.: tare must be either rounded up or kept unchanged (Pub 14 page 1-44)

The rounding off of the tare value is the method preferred by Measurement Canada. MC

may allow only this method sometime in the future.

Marking

22.1.11 The capacity and verification scale interval must be conspicuously marked near the weight display

(See section 1.1.6, 1.1.7 and 1.1.8 of this manual).

Performance Clarification

$ For any test performed on a multi-interval scale, the tolerance is a function of the verification scale

interval e of the range corresponding to the test load used.

$ The smallest value of the verification scale interval applies to the tests to determine the maximum value of

AZSM, the maximum permissible error for the return to zero test and for the creep-return to zero test, etc.

The motion detection requirement must be satisfied for each partial range. The shift test must be

performed at one-half of the capacity of each partial weighing range.

$ temperature effect on no load: the tolerance (one verification scale interval/ 5°C) applies to the smallest

verification scale interval.

$ time (half hour creep/return to zero): The deviation on returning to zero as soon the indication has

stabilized, after the removal of any load which has remained on the device for half hour, shall not

exceed 0.5 e1.

$ Devices equipped with keyboard or platter tare must meet the tolerances for net loads for any tare taken up

to the maximum tare capacity.

22.2 Multiple range devices



Definition Multiple range device means a device having two or more weighing ranges with different

maximum capacities and different scale intervals for the same load receptor, each range

extending from zero to its maximum capacity (two or more devices in one). The selection of

the range may be manual or automatic.

Number of intervals and capacity

22.2.1 Each range of a multiple range device must have the number of scale intervals (n) as required by

section 3 of the Non Automatic Weighing Devices Specifications.

22.2.2 For each range, e must equal d.

Zero setting feature

22.2.3 The zero setting feature in any weighing range must also be effective in the greater weighing ranges,

if switching to a greater weighing range is possible while the device is loaded. The deviation from

zero must be no more than 0.25 e. This is applicable to manual selection or automatic changing of

weighing ranges.

Selection of the weighing range

22.2.4 i) Manual selection of the weighing ranges is allowed from a smaller to a greater weighing range at

any load;

ii) It is allowed from a greater to a smaller weighing range when there is no load on the platter, and

the indication is zero or at a negative net value. The tare operation must be cancelled and zero

must be set to ± 0.25 e1, both automatically.

22.2.5 i) Automatic changeover of the weighing range is allowed from a smaller to the following greater

weighing range when the load exceeds the maximum gross weight of the range being operated;

ii) It is allowed from a greater to a smaller weighing range when there is no load on the platter and

the indication is zero or at a negative net value; the tare operation must be cancelled and zero

must be set to ± 0.25 e1, both automatically.

Tare features



22.2.6 The tare value may only be transferred from one weighing range to another one with a larger


22.2.7 The tare operation shall be effective also in the greater weighing range, if switching to a greater

weighing range is possible when the device is loaded.


entry (dtare = d). An attempt to enter, in the lower range of a multiple range scale, a tare value that

is not equal to d must be rejected or rounded off to the nearest scale interval.

Example A scale has a 2 g interval in the first range and 5 g in the second range. A keyboard entry of 5 g

in the first range must be either rounded to 4 or 6 g or rejected.

22.2.9 A tare value entered in the lower range must be rounded off to the nearest interval of the higher

range in which the NET weighing occurs.

Example An automatic multiple range scale has a 2 g interval from 0 to 2 kg (lower range), and 5 g from

0 kg to 10 kg (higher range). A tare of 13 g is entered in the lower range and the gross weight is

2 500 g (second range). The tare value must be rounded to 15 g and the scale must display

2 485 g (rounded off to 15 g).

Note: OIML: tare transferred only from the lowest to the largest range and rounded off to the scale interval

(R76-1, section 4.7.1).

U.S.: tare transfer only from the lowest to the largest range and must be rounded up (Publication

14, page 1-46)

22.2.10 In all cases, the mathematical equation TARE + NET must = GROSS (indicated and printed).

Indication of the range in use

22.2.11 The range in which the device operates shall automatically and clearly be indicated for both the

operator and the consumers.



Clarification If a scale has a decimal point and a different number of decimal places in each weighing range,

the position of the decimal point and the number of digits following is an adequate definition

of the weighing range in use. If the weighing range does not utilize a decimal point and

differing numbers of decimal places (e.g. scale division are 20, 50 and 100 lb), another

method must be provided to indicate the weighing range in use. A display of the capacity by

division with an annunciator located near the weight display such as the following is

acceptable:

Range in use Range 120 x 0.005 kg "

Range 5 x 0.002 kg ∋

Marking

22.2.12 Each weighing capacity by division must be clearly indicated near the weight display. If the

manufacturer chooses to indicate which weighing range is in operation using the method

recommended above (with annunciator), no other marking of capacity by division is required.

Performance

Clarification

$ Each weighing range of a multiple range scale is considered to be an individual scale and must be

evaluated accordingly.

$ temperature effect on no load. The tolerance (one verification scale interval/ 5°C) applies to the smallest


$ time (half hour creep/return to zero). The deviation on returning to zero from Max1 shall not exceed 0.5

e1. The deviation on returning to zero from Maxi shall not exceed 0.5 ei. Furthermore, after returning to

zero from any load greater than Max1, and immediately after switching to the lowest weighing range

(manually or automatically), the indication near zero must not vary by more than e1 during the following 5

minutes.

Revision

Original document


Part: 2 Section: 23 Devices Used for Direct Sale to the Public

Reference

Sections 30 to 33, 46, 47, 50, 59 and 60 of the Specifications Relating to Non Automatic Weighing Devices

(1998)

23.0 Devices Used for Direct Sale to the Public - Generalities

Several requirements apply to devices intended to be used for direct sale to the public. These requirements

are to ensure that transactions are accurate and that customers normally present during the weighing

operations are provided with sufficient information so that they can observe and understand the weighing

process.

23.1 Customer's Display

23.1.1 The device must be provided with a display (customer display) that duplicates all significant

metrological information displayed for the operator (Weight, unit price, total price, tare weight,

annunciators for "net" weight or "tare entered", centre-of-zero light, etc.); or, as a minimum, the

scale must have a connection for a separate duplicate display (Customer display must be submitted

to the Laboratory for evaluation).

23.1.2 Customers' scoreboard: Scoreboards on vehicle scales, livestock scales, etc. do not require

approval. However they must have the following features:

• the weight indication must be free floating.

• they must either indicate a negative sign or blank when the weight indication on the scale is

behind zero.

• they must blank when the weight indication exceeds the scale capacity (Max + 105%).

• they must indicate the unit of measurement. Note that a sign adjacent to the weight

indication is sufficient when there is only one unit of measurement; if there is a lb/kg switch

on the primary indicator, the scoreboard must indicate the unit in use.

• they must be able to indicate zero.

• they must indicate the weighing mode (gross, net, tare).

• Max, d and e, if different than d must be marked near the weight display.

23.2 (Reminder) See item 7.3, Section 7.0 in this manual



23.2.1 The devices must display the unit price if the total price is displayed.

23.2.2 If the device displays in kilograms, the unit price that can be entered and displayed is limited to

Price/100 g and Price/kg; if the device displays in Canadian units, the unit price that can be

entered and displayed is limited to Price/lb.

23.3 (Reminder) See item 17.4, Section 17.0 in this manual

23.3.1 Except for pre-programmed tare, proportional tares and POS systems, when keyboard or platter tare

values are entered, the scale must comply with one of the following requirement:

23.3.1.1 the tare value is permanently indicated on a separate display; or

23.3.1.2 the tare value is indicated as a negative value when there is no load on the load receptor.

23.3.2 A platter or keyboard tare value may not be entered, modified or cancelled unless the device is at

gross load zero or the device indicates a negative weight value. This does not apply when the tare

is continuously indicated on a separate display and to pre-programmed tare.

23.3.3 Platter or keyboard tares may retained between transactions.

Example A platter or keyboard tare value is entered in a computing scale; a negative value is

indicated. If the wrong tare value was entered, it may be cancelled and replaced by a new

tare value when the platter is empty. This new tare value will be indicated as a negative

weight value. However, the correction must not be possible with the commodity resting on

the platter (positive weight indication). The operator must remove the commodity from the

receptor and then cancel or change the tare value.



Clarification The zero indication/no load condition does not apply to a preprogrammed tare value. The

idea is that the operator should not be capable of altering a tare value without providing the

consumer with an indication that a new tare value was entered. In the case of a pre-

programmed tare associated with a PLU code, the tare value is rarely displayed. However, it

is unlikely that the operator will select the wrong PLU code or product name, or change the

PLU code during the weighing operation to reduce the tare value. It would affect the unit

price which would be detectable by the consumer.

23.3.4 Auto-tares are prohibited in direct sale to the public applications.

Note: Devices that are not intended for direct sale to the public but resemble those approved for direct sale

to the public, must be marked as follows: <<Not for use indirect sale to the public>> or words that

convey the same meaning. The marking must be permanent and located near the weight display so

that it is readily observable by the user.

Revision

Original document


Part: 2 Section: 24 Weigh-in / weigh-out Systems

Reference Sections 30 to 33 of the Specifications Relating to Non Automatic Weighing Devices (1998) 24.0 Weigh-in / weigh-out Systems - Generalities A weigh-in/weigh-out system is typically a vehicle scale in which an inbound truck is weighed either loaded or empty, the inbound weight is stored, the truck is then emptied or loaded as the case may be, the outbound truck is weighed and the larger of the two weights (outbound or stored weight) is printed as the gross weight, the other printed as the tare weight and the difference computed as the net weight. Inbound weights, recalled weight values, and gross, tare and net weights must be identified to clearly document the transaction. The storage, recalling, and printing actions are limited so that they do not facilitate fraud. This system does not retain inbound weights when the outbound weight is printed. The client’s file (where inbound information is stored) is cleared for the next transaction. In many cases, auxiliary equipment such as computers (software) is used to perform weigh-in/weigh-out operations. The following minimum requirements are essential to ensure that the system will not lead to measurement errors and will not facilitate the perpetration of fraud. Inspectors ensure that weigh in-out systems meet the requirements when the device is initially inspected. The followings are the main requirements for inbound/outbound weighing systems. 24.1 Any inbound weight values must be recorded and automatically identified as such (assigned to a

client name or number). If inbound weights are not printed at the time the weigh-in operation is performed, the inbound weight information must not be lost during a power interruption.

24.2 The gross, tare and net weight values must be recorded (printed) in an automatic sequence when

the outbound weight value is obtained. 24.3 The recorded weight value is not required to be automatically identified as a gross weight value,

provided that the other two weight values are clearly and automatically identified as net and tare. 24.4 If a device can indicate and/or record in two and more weight units, all gross, tare and net weight

values shall be automatically recorded in the same weight units. This condition must be met regardless which weight unit is being displayed.

24.5 Any weigh-in/weigh-out weight values stored in the memory register shall automatically clear and

not be retained in memory after a complete transaction of gross, tare and net has been recorded. 24.6 Any recorded weighing value from the memory register shall be automatically identified and

defined (client name or number). 24.7 Tare values shall not be stored as negative values. (Negative numbers shall not be accepted). 24.8 Keyboard tare entries shall not be accepted into weigh-in/weigh-out memory registers. 24.9 If the system is equipped with a tare memory register for weighing gross, tare and net weights

separate from the weigh-in/weigh-out feature, the tare weight shall not interact with the weigh-in/weigh-out feature.

24.10 The data processing system performing the weigh-in/weigh out operation shall only accept weight

values when the scale indicator is in the gross weight mode, or give an error signal.


Part: 2 Section: 24 Weigh-in / weigh-out Systems

Revision Original document


Part: 2 Section: 25 Non Metrological Functions

Reference Sections 32 and 33 of the Specifications Relating to Non Automatic Weighing Devices (1998) 25.0 Non Metrological Functions - Generalities A device may perform functions, other than metrological, such as accounting functions provided that those non metrological functions do not alter the device metrological characteristics or functions, and neither lead to measurement errors nor facilitate the perpetration of fraud. 25.1 Non metrological functions do not alter the device metrological characteristics or functions, and

lead neither to measurement errors nor facilitate the perpetration of fraud. Revision Original document


Part: 3 Section: TOC Performance Tests - Table of Contents

Part 3 - Performance Tests - Table of Contents Subject Section Linearity, Hysteresis and Repeatability at Ambient Temperature ...................................................... LG-3.01 Load Discrimination ............................................................................................................................ LG-3.02 Eccentricity ......................................................................................................................................... LG-3.03 Tilting (Off Level Position) .................................................................................................................. LG-3.04 Suitability of the Level Indicator .......................................................................................................... LG-3.05 Warm up Time ................................................................................................................................... LG-3.06 Power Interruption .............................................................................................................................. LG-3.07 AC Voltage Variations ........................................................................................................................ LG-3.08 DC Voltage Variations ........................................................................................................................ LG-3.09 Immunity to Radiated Electromagnetic Field ...................................................................................... LG-3.10 Susceptibility to Magnetism - Magnetic Loads ................................................................................... LG-3.11 Susceptibility to Magnetism - Ferromagnetic Plate ............................................................................ LG-3.12 Temperature Effect on Linearity, Hysteresis, Repeatability ............................................................... LG-3.13 Creep and Creep- Return-to-zero ...................................................................................................... LG-3.14 Temperature Effect on the No-load Indication ................................................................................... LG-3.15 Damp Heat, Steady State ................................................................................................................... LG-3.16 Electrostatic Discharge Test .............................................................................................................. LG-3.17 Short Time Power Reduction Test ..................................................................................................... LG-3.18 Burst Test ........................................................................................................................................... LG-3.19 Endurance (Permanence) Test .......................................................................................................... LG-3.20 Portability Test .................................................................................................................................... LG-3.21 Class IIIHD In-Service Limits of Error ......................................................................................... Appendix 3C Revision Rev.1 (March 2010)

• Added Portability Test • Removed appendix 3A and 3B


Part: 3 Section: 1 LG-3.01 Linearity, Hysteresis and Repeatability at Ambient Temperature

LG-3.01 Linearity, Hysteresis and Repeatability at Ambient Temperature Reference Sections 9, 10, 11, 12, 13, and 17 of the Specifications Relating to Non Automatic Weighing Devices (1998) Application This test is intended for complete mechanical or electronic weighing devices, indicating and load receiving/weighing elements tested separately.

Settings

• AZTM may be in operation during the tests. It must be set to the lowest value; if zero is the lowest

selectable value, it will be set to zero. However, the amount that the AZTM may track at once may

not be set to a value larger than 0.6e which is the maximum value allowed by the Non Automatic

Weighing Devices Specifications.

• If the IZSM range does not exceed 20% of the device capacity, tests will be performed with the

IZSM set at the upper limit of its range. The IZSM range of an indicating element tested

separately may not exceed 20%.

• If the IZSM range exceeds 20%, tests will be performed twice. A first series of tests using the lighter

platter provided by the applicant, and the second series with the IZSM set to the upper limit of its

range.

Note: In the case of a multi-range device, it is 20% of Max of the lowest range; in the case of a

multi-interval device, it is 20% of max of the first range.

• The weighing device must be leveled, adjusted as to zero error as possible and pre-loaded

(exercised) 3 times up to at least 90% Max.

• The device must be configured for the maximum capacity and smallest verification scale interval for

which the approval is sought.



• If so equipped, the "enhance resolution feature" of the device will be used during the tests. If this

feature is not available, use the small weight method to determine the device errors before rounding

(internal errors). This is not necessary if the errors are marginal.

• This test is performed at ambient temperature (≈ 20°C, or at the mid point of the temperature range

if significantly different from 20°C, and at relative humidity of ≈ 50%).

Procedure

1. Pre-condition the device: the DUT must have reached a stable temperature at ambient condition.

2. Set the device to zero.

3. Perform a minimum of three increasing and decreasing load tests to capacity using at least 5 known test weights. Loads must be centered on the load receiving element. Loads must be selected in relation to the device capacity, the value of the verification scale interval and the turning points of the tolerances. Determine the true error before rounding (internal or true errors). Record the results.

Multiple range weighing devices

1. Perform a minimum of three increasing and decreasing load tests using at least 5 known test weights in each individual range. Record the results.

2. Load the scale to the maximum capacity of the highest range (or manually select the highest

range and then load the device to capacity); Remove the load: the indications should return to zero immediately. Switch the device to the lowest range immediately (If the switch over is automatic, the device should have returned to the lowest range automatically). Note the indication near zero at the time the device switches to the lowest range. Observe the weight indication for 5 minutes. Record any changes.

Interpretation of Results Functions All functions must operate as designed and as intended. Linearity and Hysteresis Each individual result must be within the tolerance envelope as prescribed by the Non Automatic Weighing Devices Specifications. Return to Zero The device must return to zero from Max within 0.5 e for a complete device, and within 0.35 e for an indicating or load receiving/weighing element tested separately. A multiple range device must return to zero from Max I within 0.5eI. After returning to zero from any load greater than Max 1 and immediately after switching to the lowest weighing range, the indication near zero shall not vary by more than 0.5e1 during the following five minutes. Repeatability



Compare the results for each individual load of increasing and decreasing tests. The maximum difference between the results for the same load must not exceed the in-service limits of error as prescribed by the Specifications. In addition, all results must be within tolerances. Note: 1 The error of any single weighing result must not exceed the maximum limit of error for the

given load. Note: 2 A major element (module) tested separately and that is the only component of the

weighing system subject to measurement errors due to disturbance or influence factors is allowed entire applicable limits of error (i.e. a weighing element which produces an output digital signal readable by a computer).


• AZSM renamed to AZTM • Formatting changes


Part: 3 Section: 2 LG-3.02 Load Discrimination

LG-3.02 Load Discrimination Reference Sections 14, 15 of the Specifications Relating to Non Automatic Weighing Devices (1998) Application Load discrimination tests are performed on complete electronic or mechanical non automatic scales, and weighing elements tested separately using a high precision electronic indicator (Resolution must be at least ten times the DUT resolution). This test is not applicable to electronic indicators tested separately. The load discrimination test is used to determine whether the device is capable of sensing a small change of load and of changing its registration accordingly. Frictional forces, binding or system inertia can prevent a mechanical device from sensing the prescribed "Load Discrimination Test Load". Frictional forces, binding, the use of oversized (capacity) load cells, the use of an electronic indicator with an inadequate display sensitivity (μ Volts/Display Digit) or inadequate digital filter algorithms could cause an electronic weighing device to fail to detect the addition of the prescribed "Load Discrimination Test Load". Settings

• AZT may be in any status. This test is performed at the same time the increasing and decreasing load test is performed.

• If the IZSM range is limited to 20% of Max, the test will be performed with the IZSM set at the

upper limit of its range.

• If the IZSM range exceeds 20%, tests will be performed twice: with the lighter platter provided by the applicant, and with the IZSM set to the upper limit of its range.



• The device must be configured for the maximum capacity and smallest verification scale interval for which the approval is sought.

• This test is performed at ambient temperature (≈ 20°C, or at the mid point of the temperature

range if significantly different from 20°C).

• The test must be performed at zero load (or near zero) and near Max. Procedure for Digital Indicating Devices

1. If necessary, put a small load on the platter to bring the scale out of its AZT range. The indication is near zero.

2. Successively add small weights equal to 0.1 d until the ZU is reached; the indication should be

alternating between two values; remove one small weight to obtain a solid indication; the indication is at the high point of the scale interval. Record the indication.

3. Smoothly add a load equal to 1.4 d. Record the indication.

4. Repeat the test near the maximum capacity.



Note: (See IZSM points above)

Note: The test can also be done by removing the 1.4 d test weight. To do so, bring the

indication right above the ZU and then remove the 1.4 d load. Interpretation of Results The addition or removal of the 1.4 d test load must cause a change in the indication of 2 d. Procedure for Analogue Indicating Devices

1. At the no load condition, press on the platter to generate motion of the indicating element (pointer). Allow the indicator to stabilize.

2. Smoothly add (or remove) a load equal to 1.4 d and allow the indicating element to stabilize.

Record the indication.

3. Repeat the test near maximum capacity. Interpretation of Results The addition or removal of the 1.4 d test load must cause a change in the indication of 1 d. Procedure for Non Automatic Indicating Devices - Beam Scales with no Additional Means of Indication

1. Set the device to zero (beam in horizontal position at mid distance between the trig loops or the limiting stops).

2. Add or remove a load equal to 1 d (in-service limit of error) when the test is performed near zero.

3. Repeat the test near maximum capacity. Add or remove a small load corresponding to the in-

service limit of error applicable to the load on the platter, without exceeding 2 d. Interpretation of Results The addition or removal of the test load must cause the weighbeam to change from the center position to the outer limit of the trig loop or limiting stops. Procedure for Non Automatic Indicating Devices - Beam with Additional Indicating Means (over/under indicator having graduations without assigned values)


2. Add or remove a load equal to 1 d (in-service limit of error) when the test is performed near zero.

3. Repeat the test near maximum capacity. Add or remove a small load corresponding to the in-service limit of error applicable to the load on the platter, without exceeding 2 d.



Interpretation of Results The addition or removal of the test load must cause the position of the indicator to change by the distance indicated below:

• 1 mm for Class I and II devices; • 2 mm for Class III and IIII devices with a Max ≤ 30 kg; • 5 mm for Class III, III HD and IIII devices with a Max > 30 kg.


• AZSM renamed to AZT • Formatting change


Part: 3 Section: 3 LG-3.03 Eccentricity

LG-3.03 Eccentricity

Reference Sections 9, 10, 11, 12 and 14 of the Specifications Relating to Non Automatic Weighing Devices (1998)

Application Eccentricity tests are performed on complete devices and weighing elements tested separately. Shift tests are also performed on single point hanging scales if the load receptor is relatively large. The purpose of this test is to reveal the ability of load cell(s), load cell mounting and check systems of a weighing element to resist or compensate for the torsion effects of non axial loads. This test also ensures that the load cells of electronic scales, the levers of mechanical scales, or both in the case of electromechanical scales, are adequately "balanced" in order to obtain accurate weighing. The device must be capable of weighing accurately in spite of changes of position of the test load over the load receiving element.

Settings • AZT should be disabled (OFF) or the scale must be prevented from returning to ZERO during the

test. When practical, this test can be performed while performing Increasing/Decreasing load tests.

• If the IZSM range does not exceed 20% of the device capacity, tests will be performed with the

IZSM set at the upper limit of its range.

• If the IZSM range exceeds 20%, tests will be performed twice. A first series of tests using the lighter platter provided by the applicant, and the second series with the IZSM set to the upper limit of its range.



• The device must be set for the maximum capacity and smallest verification scale interval for which the approval is sought.


feature is not available, use the small weight method to determine the device errors before rounding.

• This test is performed at ambient temperature (≈ 20°C); or at the mid point of the temperature

range if significantly different from 20°C.

Procedure for bench, counter or hanging scales, other platform scales, equal arm scales and forklift or hand-truck scales with load receiving elements having no more than four points of support.

1. Stabilize the device at nominal conditions; zero the device.

2. Apply a test load equal to 1/3 Max on the center of the platter (Position #1). Record the indication.



3. Apply the same test load on the device in such a manner that the center of gravity of the test load lies approximately at the center of one of the numbered target boxes in the following illustrations. Record the indication.

4. Proceed in the same manner with the other points of application. Avoid sliding weights on the LRE.

Instead, weights must be picked and placed back down on the LRE. Record the indications. Note: 25% of Max placed on the LRE over the load cell may also be use to perform corner tests

on platform, floor or bench scales having 4 support points. Number of Support Points ≤ 4

Platform Scale - More Than Four Support Points

Procedure Larger platform scales and other scales with more than four points of support

1. Zero the device. 2. Apply a test load equal to 1 / (n-1) of Max to the center of the platter (Position number 1). Record

the indication. (n = number of support points) 3. Divide the surface area of the LRE into 1/n segments, each over one of the load support points. 4. Apply the same test load on the device in such a manner that the center of gravity of the test load

lies at the center of each segment. (n = number of support points). Record the indication. 5. Proceed in the same manner with each of the other segments. The test load should not overhang

the edge of the LRE. Record the indication. 6. Using the appropriate loading pattern below, perform the same tests as above. Weights should be

placed upon the largest pallet typically lifted by the forklift or hand-truck. If the forks are adjustable, repeat test at both minimum and maximum fork spacing.

7. Due to the nature of these pieces of equipment, extreme care must be taken to ensure that the stability of the forklift or hand-truck is not compromised during the test. Testing should always be done with the forks in the lowered position.



Forklift or Hand-Truck Scales

Forklift – All Configurations



Hand Truck – 3 Supports

Monorail Scales 1. Zero the device.

2. Apply a rolling load corresponding to the usual rolling load, the heaviest and the most concentrated

one which may be weighed, but not exceeding 80% of Max at different points of the load receiving element.

3. Record the indications.

During this test, observe the rail to detect any inappropriate motion, deflection, binding or friction that could adversely affect the scale performance.

Tank or Hopper Scales 1. Zero the device.

2. Use a load of at least 10% of Max without exceeding 25% of Max. Apply the load to each point of

support. Care must be taken to keep the center of gravity of the load between the supporting points to prevent cantilevering the scale.

3. Record the indications.

Note: The ratio between the test load and e must be such that it will be possible to establish the error

and apply the limits of error.



Section / Shift Tests on Vehicle Scales Vehicle Scale – 4 Sections

Maximum Concentrated Load The axle (or set of axles) weight of the vehicle used must not be greater than 75% Max in the case of a two section scale, and not greater than 50% Max in the case of scale with more than two sections.

Procedure 1. Zero the device

2. Drive the loaded vehicle onto the weighbridge and position the center of the heaviest set of axles

over the first section; record the indication.

3. Move the concentrated load over the second section. Record the indications.

4. Repeat the procedure for each of the other sections.



5. Enter the weighbridge in the opposite direction and test each section again. At least two complete sets of shift tests should be conducted over each section of the scale. This is to determine the repeatability of the scale.

Note: The last section in each direction, before leaving the scale, cannot be adequately loaded with a

typical test truck. The final stopping position should be just before the first set of axles leaves the weighbridge.

Shift Test – Deflection The concentrated load must also be placed between the sections to determine if any deflection of the deck or understructure is causing inaccuracies. Vehicle Scale - Deflection

Note: When using a loader to conduct a shift test, the center-of-gravity (CoG) should be position over

the load cell(s). This position will change depending upon the configuration of the machine. In addition, loaders, when used as strain or shift test loads should have their buckets / grapples in lowered positions if possible. This lowers the CoG and reduces the Asail@ effect from the wind.

Shift Test - Wide Deck If the width of the weighbridge exceeds 3 meters (or when the inspector deems it necessary), perform a first series of tests with the vehicle shifted on the right side of the deck and then shifted to the left side. Warning: Wide Deck shift test should not be attempted on wooden deck scales if the test means

driving the vehicle off of the longitudinal timbers intended to support the tires. The transverse mounted decking may not have adequate strength to support the concentrated load of the vehicle.



Shift Test - Modular Scales In the case of weighbridge made of modules (multi-deck vehicle scale), shift tests must also be conducted by placing the load so that it straddles the connection between the modules. At least one shift test is to be conducted on the scale with the test load place on one side of the connection line of the module, then on the other side of the connection line. Vehicle Scale - Modular

Use of Hydraulic Jack The use of weight truck hydraulic jack beam is prohibited for safety reasons.



Vehicle Scale Mounted Side by Side

Procedure Vehicle Scales mounted in non-traditional fashion. Often used for weighing of off-road mining equipment or large logging equipment. These scales usually consist of two scale decks mounted side by side, however other configurations are possible including a “T” configuration.

1. Zero the device.

2. If possible, test eccentricity on each scale separately using the loading patterns for vehicle scales as above. Then continue with the following tests.

3. Drive a loaded vehicle onto the weighbridge and position the center of the heaviest set of axles

over the first support point/section; record the indication.

4. Move the concentrated load over the second load point/section. Record the indications.

5. Repeat the procedure for each of the other load points/sections.

6. If possible, enter the weighbridge in the opposite direction and test each load point/section again.

7. Testing should approximate normal use loading patterns as much as possible. Vehicle Scale – Side by Side

Interpretation of the Results The difference between the results for different positions of the load must not exceed the absolute value of the In-Service Limit of Error for that load. Each individual result must also be within the applicable limits of error for the test.

Revision Rev. 1 (November 2004)

• Change reference from “load cell” to “support point” to cover all scale types. • Added eccentricity drawing for Forklift, single support. • Corrected number of support points reference in platform scales (≤4). • Added procedure for platform scales with more than four support points. • Added procedure for “side by side“ deck vehicle scales.



Rev. 2 (April 2005) • Modified & simplified forklift / hand truck loading requirements.

Rev. 3 (September 2009)

• Modified test weight to 1/3 capacity • Removed diagram for bench/counter scales with a single support point (test point now same for

all devices up to 4 support points) Rev. 4 (March 2010)

• AZSM renamed to AZT • Formatting changes


Part: 3 Section: 4 LG-3.04 Tilting (Off Level Position)

LG-3.04 Tilting (Off Level Position)

Reference

Sections 9, 10, 11 and 22 of the Specifications Relating to Non Automatic Weighing Devices

Application

This test is performed on any complete portable or movable devices or weighing elements tested separately,

that are of a type other than suspended, and that are not equipped with a suitable level indicating means.

Devices aimed are: bench and counter scales, floor scales, weighing systems mounted on a vehicle (On-

board weighing systems for NH3, on-board waste weighing systems, scales mounted on lift trucks).

"Portable" vehicle scales do not fall into this category. The purpose of this test is to ensure that the

performance is not affected when the device is off level.

Settings • The AZT may be activated. It must be set so that the weight value that can be tracked at once

does not exceed 0.6 e.

• If the IZSM range does not exceed 20% of Max, the test will be performed with the IZSM set at the maximum of the range.

• If the IZSM range exceeds 20%, the test will be performed twice: the first test with the IZSM set to

the lowest possible value; the second test with the IZSM set to the to the maximum of its range.

Note: In the case of a multi-range device, it is 20% of Max of the lowest range; in the case of a multi-interval device, it is 20% of max of the first range.

• If the device has an "enhance" resolution feature, perform the test with that feature activated; or

use the small weight method to determine errors before rounding.

• This test is performed at ambient temperature only. Figure 1 : Off Level by 3 Degrees Calculation - Example

Measure the distance “x” between the two support points of the scale. Multiply the “x” value by 5/100 (0.05 or approx Tan 3°). The result is the elevation “y” at the support point. Note: The device is tested for accuracy when leveled, first; then off-level tests are performed.



Procedure for Portable or Movable Scales 1. The procedure consists of inclining the device in the four directions (+x, -x, +y, -y) using a suitable

support. The tests is performed when the device is off level by the lesser of: a) 3 degrees; or b) maximum angle at which the device still provides an indication or registration.

2. For each of the four inclinations, set the device to zero and perform an increasing and decreasing load test.

Note: It is not necessary to proceed further if at the first inclination the device does not perform

within the prescribed limits of error.

Interpretation of Results The device meets the requirements if it performs within prescribed limits of error when off level. Note: If the device can not perform within the prescribed limits of error, it must be equipped with a

suitable level indicating means permanently installed.

On-board weighing systems such as systems for forklift trucks or similar vehicles

Definition On board weighing system means weighing device designed to be an integral part of, or attached or secured to, the frame, chassis, lifting mechanism or bed of mobile equipment such as a truck, tractor, trailer or forklift

Level Testing 1. With the vehicle resting on a level surface, visually inspect, checking for possible binding and

additional items secured to the device that may have an effect on accuracy (e.g. mudflaps and fenders must be secured to the frame of the vehicle, not the device).

2. Perform load discrimination tests near zero and at capacity; increasing and decreasing load tests;

section/corner tests; repeatability; blanking at capacity and motion detection; return to zero; etc.. The device must perform within the prescribed limits of error.



Off Level Test 1. Visually inspect the device while performing the following tests to ensure that the inclination does

not cause a shift that may affect the device accuracy.

2. Elevate the front or rear wheels to 3 degrees or the maximum inclination at which a weight indication is still provided, whichever is greater. Perform the tests described under "level testing" above, except the section and repeatability test.

3. Elevate either the driver side or passenger side to 3 degrees or the maximum inclination at which a

weight indication is still provided, whichever is greater. Perform the tests described under "level testing" above, except the section and repeatability test.

4. Elevate a single rear wheel combination until the side to side inclination is 3 degrees or the point at

which a weight indication is still provided, whichever is greater. This test causes the frame to twist and will reveal defects in poorly constructed devices. Perform the tests described under "level testing" above, except the section and repeatability test.

5. Scales mounted on lift trucks (or similar vehicles) must blank their indications when the lift truck is

moving, unless the scale can provide an accurate weight indication. Perform an accuracy (in-motion) test using different loads within the capacity range of the device. The test must simulate actual conditions of use.

Interpretation of the Results The device meets the requirements if:

• it provides a weight indication when off level up to at least 3 degrees; • it performs within the prescribed limits of error when off level by the larger of 3 degrees or the

maximum angle at which it still provides a weight indication; • it blanks its indications and prevent the recording of weight values when it ceases to perform

within tolerances; • in the case of a scale mounted on a lift truck, it provides weight indications within the permissible

limits of error while the lift truck is moving, or blanks its indications.


• AZSM renamed to AZT • Formatting changes


Part: 3 Section: 5 LG-3.05 Suitability of the Level Indicator

LG-3.05 Suitability of the Level Indicator Reference Sections 9, 10, 11 and 22 of the Specifications Relating to Non Automatic Weighing Devices (1998). Application This test is intended for complete portable or movable devices and weighing elements whose performance is affected when off level. Such devices must be equipped with a suitable level indicating means. This test is to ensure that the level indicating means is sensitive enough to accurately indicate the limit of inclination at which the device ceases to perform within tolerances. Settings

• The AZT may be activated. It must be set so that the weight value that can be tracked at once does not exceed 0.6 e.

• If the IZSM range of the device does not exceed 20% of Max, the test will be performed with the

IZSM set at the maximum of the range.

• If the IZSM range exceeds 20% of Max, the test will be performed twice: the first test with the IZSM set to the lowest possible value; the second test with the IZSM set to the to the maximum of its range.



• The device must be leveled using the level indicating means, and adjusted to as close to zero error as possible.



• This test is performed at ambient temperature only. Procedure

1. Incline the DUT in one direction (arbitrarily referred to as -x) up to the point of limit where the level indicating means still indicates a level condition or at least 2/1 000 (0.12 degree) whichever is greater.

2. Set the device to zero if necessary; perform an increasing and decreasing load test. If necessary,

use the small weight method to find errors before rounding. Record the results.

3. Record the angle with reference to the horizontal

4. Repeat the test described above for the other three inclinations (+x, -y, +y) (See the following illustrations).


Part: 3 Section: 5 LG-3.05 Suitability of the Level Indicator

Off Level: -X direction

Off Level: X direction

Off Level: Y direction

Interpretation of Results The device meets the requirements if, at the limits of inclination in all four directions, it performs within applicable limits of error. Revision Rev. 1 (March 2010)



Part: 3 Section: 6 LG-3.06 Warm Up Time

LG-3.06 Warm Up Time Reference Sections 9, 10, 11, 31 and 32 of the Specifications Relating to Non Automatic Weighing Devices (1998) Application This test is intended for any electronic devices and electronic major components. The purpose of this test is to ensure that weight indications provided by a device while it warms up are accurate. Settings

• The AZT should be disabled (OFF). If it cannot be disabled, it must be set to the lowest value; if zero is the lowest selectable value, it must be set to zero. The amount that the AZT may track at once may not be set to a value larger than 0.6 e which is the maximum value allowed by the Specifications.

• The IZSM will be set to the maximum of its range.

• The device must have been set to as close to zero error as practicable.



• This test is performed at ambient temperature only. Procedure

1. Turn off and disconnect from the power source the DUT for a period of at least eight (8) hours (i.e. disconnect a wall mount transformer or pull the plug of AC device; remove the batteries of a DC device).

2. Re-connect the DUT to the power source and switch it "on".

3. Record the first available indication (i.e. the first indication that can be used for the purpose of the

transaction).


5. Apply a load equal to at least 70% of Max and record the indication. Interpretation of Results The device meets the requirements if the first weight indications available are within the applicable limits of error. Otherwise, weighing operations (printing or indicating weight values) must be inhibited during the warming up period. Note: OIML Recommendation R76 (A.5.2) - re-read the device at 5 minutes, 15 minutes and 30 minutes after power on. Each reading, when corrected for zero error at the time, must be within the applicable LOE.


Part: 3 Section: 6 LG-3.06 Warm Up Time


• AZSM renamed to AZT


Part: 3 Section: 7 LG-3.07 Power Interruption

LG-3.07 Power Interruption Reference Sections 9, 10, 11, 31 and 32 of the Specifications Relating to Non Automatic Weighing Devices (1998) Application This test is performed on complete electronic scales and electronic indicators tested separately. This test is to ensure that momentary power failures that can occur during weighing operations will not lead to measurement errors that can not be easily detected. This test also applies to battery-powered devices where the battery is replaceable or rechargeable. Settings

• Removable or rechargeable battery must be disconnected; the AZT may be in any status. Procedure

1. Place a load on the load receiving element and zero the device (by activating the non-automatic zero setting mechanism).

2. Place an additional load on the load receiving element and note the registration.

3. Unplug the DUT by pulling the plug and, in no less than five (5) and no more than ten (10)

seconds, restore the power to the DUT and record the manner the scale returns to operation. Note the registrations.

4. Repeat the test, but this time interrupt the power using the power switch of the DUT.

5. Repeat the test with a Keyboard or Platter tare entered; repeat the test with preprogrammed tares

entered (i.e. tares associated to PLU codes); repeat the test with an "in-bound" weight entered. Interpretation of Results The DUT is deemed to comply with the requirements if, after interrupting and restoring the power to the DUT, the registration has:

• returned to zero within the prescribed range; or

• returned to an accurate weight value; or

• display a meaningless output or error signal which requires operator intervention.; and

• retained the information in memory (In-bound weights and uncompleted transactions shall not be lost during a power failure or when restarting the system).




Part: 3 Section: 8 LG-3.08 AC Voltage Variation

LG-3.08 AC Voltage Variation Reference Sections 9, 10, 11 and 27 of the Specifications Relating to Non Automatic Weighing Devices (1998) Application This test is performed on any complete electronic devices or major electronic components powered from an AC source. Self-powered weighing elements will be submitted to this test. Voltage variations are susceptible to occur during the normal use of devices. The purpose of this test is to ensure that voltage variations do not affect the device performance. Settings

• AZT may be in operation during the tests. It must be set to the lowest value; if zero is the lowest selectable value, it will be set to zero. The amount that the AZT may track at once may not be set to a value larger than 0.6 d which is the maximum value allowed by the Specifications.

• If the IZSM range does not exceed 20% of Max, tests will be performed once with the IZSM set at

the upper limit of its range.


• If the IZSM range exceeds 20% of Max, tests will be performed twice: a first series of tests using

the lightest platter provided by the applicant and the second series with the IZSM set to the upper limit of its range.

• The weighing device must be leveled to its reference position.

• The device must be set for the maximum capacity and smallest verification scale interval for


• If so equipped, the "enhance resolution feature" of the device will be used during the tests. If this feature is not available, use the small weight method to determine the device errors before rounding.

• This test is performed at ambient temperature (≈ 20°C); or at the mid point of the temperature

range if significantly different from 20°C; and ≈ 50% RH.

• Power source must be stable to within ± 2% Procedure

1. Let the Power Supply and the DUT warm up for the minimum time recommended by the manufacturer.

2. Decrease the voltage to the minimum voltage specified.

3. Perform an increasing and decreasing test and record the results.

4. Activate the device functions to ensure they operate normally (tare, print, motion detection, etc.)


Part: 3 Section: 8 LG-3.08 AC Voltage Variation

5. Record the following data: a) time, b) temperature, c) relative humidity, d) voltage, e) loads, f)

indications, g) errors, and h) note any malfunctions of the features.

6. Increase the power supply voltage to the maximum voltage specified; repeat steps 3, 4 and 5. Maximum and minimum voltage specified

• If the nominal voltage is not indicated on the marking plate, 117 volts or 225 volts, as the case may be, is deemed to be the nominal voltage. Then, the minimum and maximum voltage are 100 volts or 191 volts (-15%) and 129 volts or 247.5 volts (+10%) respectively.

• If the marking plate indicates a nominal voltage other than 117 volts, the indicated voltage will be

considered as the nominal voltage. The minimum and maximum voltage will be calculated from the nominal voltage indicated on the plate.

• If a voltage range is indicated ( i.e. 100 volts to 130 volts), the test will be performed at

Vmin - 15% and again at Vmax + 10%

• If the device ceases to indicate weight values while the voltage is well within the -15% / +10% range limits, the tests will be performed at the limits of indication.

Interpretation of results The DUT is deemed to have met the requirements if, during the voltage variations, the device:

• operates within the prescribed limits of error and all the functions operate normally; or • ceases to display weight and price values and prevents the transmission and storage of data.


• AZSM renamed to AZT • Formatting change • Procedure altered to change specified voltages with devices that operate over a range of voltages • Removed requirement for an increasing/decreasing test at nominal voltage


Part: 3 Section: 9 LG-3.09 DC Voltage Variation

LG-3.09 DC Voltage Variation

Reference Sections 9, 10, 11 and 27 of the Specifications Relating to Non Automatic Weighing Devices (1998)

Application This test is performed on any complete electronic devices or major electronic components that operate from a DC power source (Batteries or other DC sources, but not through an AC/DC adapter). Self-powered weighing elements will be submitted to this test. Voltage variations are susceptible to occur during the normal use of devices. The purpose of this test is to ensure that voltage variations do not adversely affect the device performance and normal operating characteristics. DC power operated devices must continue to operate normally despite of a power reduction to the point where no weight indication is provided and power increase by 10% of the nominal value.

Settings • AZT may be in any status. If "on", it must be set to the lowest value; if zero is the lowest

selectable value, it will be set to zero. The amount that the AZT may track at once may not be set to a value larger than 0.6 d which is the maximum value allowed by the Specifications.

• If the IZSM range does not exceed 20% of Max, tests will be performed with the IZSM set at the

upper limit of its range.


• If the IZSM range exceeds 20%, tests will be performed twice: a first series of tests using the

lighter platter provided by the applicant and the second series with the IZSM set to the upper limit of its range.

• The weighing device must be leveled to its reference position.




• This test is performed at ambient temperature (± 20°C); or at the mid point of the temperature

range if significantly different from 20°C; and ±50% RH.

• Power source must be stable to within ±2%

Procedure 1. Let the Power Supply and the DUT warm up for the minimum time recommended by the

manufacturer.

2. Decrease the voltage until the device ceases to provide a weight indication. Increase the voltage until the device resumes the indication; re-zero.


Part: 3 Section: 9 LG-3.09 DC Voltage Variation

3. Perform an increasing and decreasing test and record the results.

4. Activate the device functions to ensure they operate normally (tare, printing, motion detection, etc.)

5. Record the following data: a. time, b. temperature, c. relative humidity, d. voltage, e. loads, f. indications, g. errors, and h. note any malfunctions of the features.

6. Increase the power supply voltage up to 10% above the device nominal voltage; re-zero and repeat

steps 3, 4 and 5 Note: It may be necessary to increase the voltage beyond the limit point of display, and then decrease

the voltage in order to be able to reach the lowest voltage at which an indication is provided. Some devices have an extended voltage range, for instance from 12 to 72 DC volts. In such a case, the device will be tested at the lowest voltage where a weight indication is provided and 10% above the high limit of the voltage range.

Interpretation of Results The DUT is deemed to have met the requirements if during the voltage variations the device:

• operates within the prescribed limits of error and all the functions operate normally; or • ceases to display weight and price values and prevents the transmission and storage of data.


• AZSM renamed to AZTM • Formatting change • Removed requirement for an increasing/decreasing test at nominal voltage


Part: 3 Section: 10 LG-3.10 Immunity to Radiated Electromagnetic Field

LG-3.10 Immunity to Radiated Electromagnetic Field

Reference Section 30 of the Specifications Relating to Non Automatic Weighing Devices (1998)

Application This test is performed on any complete weighing devices and major elements that incorporate electronic components susceptible to be affected by radiated electromagnetic fields. This test consists of exposing the device to an electromagnetic field emitted by radio transmitters at frequencies of 27 MHz and 460 MHz with an intensity of up to ≈ 3 V/m. Note to the attention of device manufacturers This test method will be used until Measurement Canada acquires the necessary facilities and equipment to perform immunity to radiated electromagnetic field tests over the entire 26 MHz to 1 000 MHz range as recommended by OIML, R76-1).

Settings • The AZT can be in any status.

• Ensure that the radio transceiver batteries have been fully charged.

• Set the IZSM to the maximum of its range.

• The test is performed at ambient temperature only ( ≈ 20°C and ≈ 50% RH).

• The field strength will be measured using an appropriate field strength meter; results of tests while

the field intensity exceeding ≈ 3 V/m will not be considered.

• The determination of error before rounding using the small weights method is not necessary.

Procedure 1. Place, on the platter of the device, a load approximately equal to 2 Max. Record the value

displayed.

2. Perform a summary test at each radio frequency by bringing the radio antenna close to the DUT at various angles (orientations), above, around and under the device; observe the indication. If the device does not appear to be affected by the RFI, then there is no need to proceed further. If the device is affected, it will be necessary to repeat the test, and this time to measure the field strength at the device.

3. Place the field strength meter in close proximity to the device. Using the handheld radio

transmitters, expose the DUT to field strength equal to ≈ 3 V/m. Bring the antenna around, above and under the device, at different angles. Attempt to maintain the field intensity at the device at ≈ 3 V/m. Observe the indication during the test and attempt to print weight values. Record the results. Do not consider the results obtained while the field strength exceeds ≈ 3 V/m.


Part: 3 Section: 10 LG-3.10 Immunity to Radiated Electromagnetic Field

Interpretation of results The device meets the requirements:

• if the weight indications and registrations with and without disturbance do not exceed the value of e;

or

• if the device detects and reacts to a significant fault as follows:

o blanks the indication and prevent the printing of weights; or o provides an error message and prevent weighing; or o provides an indication that is completely unstable so that it is not interpreted, or

transmitted into memory or to the recording element as a correct measurement value.


• AZSM renamed to AZT • formatting change


Part: 3 Section: 11 LG-3.11 Susceptibility to Magnetism - Ferromagnetic Loads

LG-3.11 Susceptibility to Magnetism - Ferromagnetic Loads


Application This test is performed on any complete weighing devices and load weighing elements that incorporate load cells functioning on the principle of "electromagnetic force compensation ".


• The test is performed at ambient temperature only (≈ 20°C and ≈ 50% RH).

Procedure 1. Place a separator block of appropriate height on the load receiving element and zero the device.

Place a test weight ≈ 2 Max made of a ferromagnetic material (iron or steel) on top of the separator block. Note the indication and remove the test weight.

2. Remove the separator block, re-zero the device, place the test weight from step 1 directly on the

load receiving element and note the indication. Note: Separator block should be high enough to significantly reduce the effect on the test weight of any magnetic field created by the device. It should be lightweight, non-metallic and anti-static.

Interpretation of Results The DUT meets the requirements if the difference between the two indications is no greater than the in-service limit of error for that load.


• AZSM renamed to AZT • formatting change

Rev. 2 (April 2010)

• Complete revision to procedure


Part: 3 Section: 12 LG-3.12 Susceptibility to Magnetism - Ferromagnetic Plate

LG-3.12 Susceptibility to Magnetism - Ferromagnetic Plate


Application This test is performed on any complete weighing devices and load weighing elements that incorporate load cells functioning on the principle of "electromagnetic force compensation".


• The test is performed at ambient temperature only (≈ 20°C and ≈ 50% RH).

• The DUT must have been tested prior to the following test, and must perform within applicable

LOEs.

Procedure 1. Place the DUT on a ferromagnetic plate (steel or iron). Zero the DUT.

2. Perform an increasing and decreasing load test.

Interpretation of Results The DUT meets the requirements if the indication obtained using the ferromagnetic material is within the prescribed LOEs.


• AZSM renamed to AZTM • Formatting change


Part: 3 Section: 13 LG-3.13 Temperature Effect on Linearity, Hysteresis, Repeatability

LG-3.13 Temperature Effect on Linearity, Hysteresis, Repeatability

Reference Sections 9, 10, 11, 12, 13, 17 and 25 of the Specifications Relating to Non Automatic Weighing Devices (1998)

Application This test is intended for any complete devices and major components (including Analogue to Digital signal converters) incorporating electronic components susceptible to be affected by temperature fluctuations. This test is to be performed also on mechanical scales using temperature compensated springs. The purpose of this test is to ensure that devices are able to measure within applicable limits of error at any temperatures between -10°C to 40°C, unless otherwise marked on the device Not all devices are affected by all of the influence factors, hence not all influence factor tests need to be performed on all devices. For example, indicating elements that processes only digital information (slave display) do not have to be tested for compliance under influence factors.

Settings • AZT may be in operation during the tests. It must be set to the lowest value; if zero is the lowest

selectable value, it will be set to zero. The amount that the AZT may track at once can not exceed 0.6 e which is the maximum value allowed by the Specifications.

• If a device is provided with an IZSM, the tests will be performed once with the IZSM set to the maximum of its range.

• The weighing device must be leveled to its reference position • Except for zero-setting, the device must not be adjusted or re-adjusted at any time during the test. • The device must be set for the maximum capacity and smallest verification scale interval for

which the approval is sought. • If so equipped, the "enhance resolution feature" of the device will be used during the tests. If this


• This test is performed at the following temperatures:

First round: at nominal temperature (≈ 20°C, or at the mid point of the temperature range if significantly different from 20°C); Second round: at low temperature (- 10°C, or the lower point of the temperature range marked

on the device); Third round: at high temperature (+ 40°C, or the higher point of the temperature range marked

on the device). Fourth round: at nominal temperature (≈ 20°C, or at the mid point of the temperature range if significantly different from 20°C).



• When the environmental chamber has reached the desire temperature, allow a minimum of 2 hours after the DUT temperature has stabilized.

Note: The temperature of the DUT can be monitored by attaching a thermocouple with adhesive tape inside the DUT onto a component of relatively large mass. However, the thermocouple must not be attached to any live component(s) of the DUT. The temperature will be deemed to be stable when the temperature obtained from the thermocouple will have stabilized within ± 1°C. Once stabilized, the temperature obtained from the thermocouple will likely be different than the overall temperature of the environmental chamber. The requirement is only that the temperature of the DUT stabilizes to within ± 1°C.

• Moisture content in the environmental chamber must not exceed ≈ 50% RH at test temperatures. • The test equipment such as load cell simulators, high precision reference indicators, must be

isolated from the test conditions and maintained at constant ambient temperature and humidity. • Note that the following tests are performed together: temperature effect on linearity and

hysteresis, creep and temperature effect on no load condition.

Procedure

For Single Range or Multi-Interval Weighing Devices 1. If the device has been moved perform the test described in LG-3.21 2. With the DUT switched "on" and in the environmental chamber, stabilize the DUT at ≈ 20°C.

Monitor the temperature of the DUT until it has reached stability. Wait an additional 2 hours. 3. Exercise (3 times up to at least 90% Max) the DUT; set the DUT to zero. 4. Perform at least two increasing and decreasing load tests to capacity using at least five known

weights. Loads must be selected in relation to the device capacity, the value of the verification scale interval and the turning points of the tolerances. Determine the true error before rounding. Record the following data:

a) time, b) temperature, c) relative humidity, d) loads, e) indications, f) errors, and g) note any malfunctions of the device features.

5. Repeat the test sequence at -10°C, + 40°C (or at the lowest and highest temperatures marked on the device). Record the following data:

a) time, b) temperature, c) relative humidity, d) loads, e) indications, f) errors and g) note any malfunctions of the device features.

For Multiple Range Weighing Devices 1. If the device has been moved perform the test described in LG-3.21 2. Set the device to zero in the lowest range. Perform two increasing and decreasing load tests using

at least 5 known weights. 3. Repeat the test for the other ranges.



4. Load the scale to the maximum capacity of the highest range (or manually select the highest range and then load the device to capacity); remove the load: the indications should return to zero immediately. Switch the device to the lowest range immediately (If the switch over is automatic, the device should have returned to the lowest range automatically). Note the indication near zero at the time the device switches to the lowest range. Observe to weight indication during the next 5 minutes and record any changes.

5. Repeat the test sequence at -10°C, + 40°C (or at the lowest and highest temperatures marked on the device). Record the following data:

a) time, b) temperature, c) relative humidity, d) loads, e) indications, f) errors and g) note any malfunctions of the device features.

Interpretation of results • All functions of the device must operate as designed.

• Linearity and hysteresis

Each individual result must be within the tolerance envelope as prescribed by the Specifications.

• Repeatability Compare the results for each individual load of increasing and decreasing tests. The maximum difference between the results for the same load must not exceed the in-service tolerances as prescribed by the Specifications.

• Return to zero

The device must return to zero from Max within 0.5 e for a complete device, and within 0.35 e for indicating or load receiving/weighing elements tested separately.

A multiple range device must return to zero from Maxi within 0.5 ei. After returning to zero from any load greater than Max1 and immediately after switching to the lowest weighing range, the indication shall be within 0.5 e1 . Note: the error of any single weighing result must not exceed the maximum limit of error for the given

load. Note: The following tests are grouped and performed in a pre-determined sequence: LG-3.13

Temperature Effect on Linearity, Hysteresis, Repeatability; LG-3.14 Creep and Creep-Return-to-Zero; LG-3.15 Temperature Effect on the No-Load Indication; See the Recommended Test Sequence.


• AZSM renamed to AZT • Test procedure altered to reference LG-3.21


Part: 3 Section: 14 LG-3.14 Creep and Creep - Return-to-Zero

LG-3.14 Creep and Creep - Return-to-Zero

Reference Sections 17 and 18 of the Specifications Relating to Non Automatic Weighing Devices (1998)

Application This test is performed on any complete mechanical or electronic weighing device and on any mechanical or electronic weighing element tested separately.

Settings • The AZT should be disabled for this test. If it cannot be disabled it must be set to the lowest value;

if zero is the lowest selectable value, it will be set to zero. The amount that the AZT may track at once can not exceed 0.6 e which is the maximum value prescribed by the Specifications.

• If a device is provided with an IZSM, the tests will be performed once with the IZSM set to the

maximum of its range.




• The creep and creep-return to zero tests are performed at ambient (≈ 20°C) temperature only.

• Note that these tests are combined with the test performed to assess the temperature effect on

linearity and hysteresis.

• The temperature of the DUT must have stabilized to within ± 1°C. Note: The temperature of the DUT can be monitored by attaching a thermocouple with adhesive tape inside the DUT onto a component of relatively large mass. However, the thermocouple must not be attached to any live component(s) of the DUT. The temperature will be deemed to be stable when the temperature obtained from the thermocouple will have stabilized within ± 1°C. Once stabilized, the temperature obtained from the thermocouple will likely be different than the overall temperature of the environmental chamber. The requirement is only that the temperature of the DUT stabilizes to within ± 1°C.

• Moisture content in the environmental chamber must not exceed ≈ 50% RH at test temperatures.

• The test equipment such as load cell simulators, high precision reference indicators, must be

isolated from the test conditions and maintained at constant ambient temperature and humidity.

• The increasing and decreasing load tests must be performed before the creep test and creep-return-to-zero test; a recovery time period equal to the accuracy (increasing and decreasing) test time is permitted before conducting the creep test; the scale should be exercised 3 times up to at least 90% Max before conducting the creep and creep-return-to zero test if an extended period of time has passed since the scale was last tested.



Procedure

Single Range or Multi-Interval Device

Creep Test 1. Following the increasing and decreasing load test, allow the device to "recover" for a period of time

equal to the increasing and decreasing test time. Exercise the scale 3 times up to at least 90% Max.

2. Place on the weighing element a load equal to at least 90% of Max, and take a reading 20 seconds

after the indication has stabilized. Observe the indication for 30 minutes, taking a reading at 15 minutes and 30 minutes. Do not remove the load

Creep - Return to Zero Test 3. Remove the load and take a reading as soon as the indication has stabilized (wait no more than 20

seconds). If the AZT could not be disabled leave a small weight on the platter to keep the indication above the AZT range.

Multiple Range Devices

Creep Test 1. Complete the creep test described for Single Range or Multi-Interval Devices for each range,

using 90% of the Max of the range being tested.

Creep - Return to Zero Test 2. After the creep test for the lowest range has been completed remove the load and take a reading

as soon as the indication has stabilized (wait no more than 20 seconds). If the AZT could not be disabled leave a small weight on the platter to keep the indication above the AZT range.

3. After the creep test for the highest range (using 90% of the capacity of the device) Remove the

load and take a reading as soon as the indication has stabilized (Wait no more than 20 seconds). If the AZT could not be disabled leave a small weight on the platter to keep the indication above the AZT range.

4. Immediately, switch the device to the lowest range, take a reading of the weight indication.

Observe the weight indication for 5 minutes. Record any changes in the weight indication.

Interpretation of Results (Creep Test) The device meets the requirements if the difference between the indication obtained 20 seconds after placing the load on the device and the indication observed during the following 2 an hour does not exceed the absolute value of the applicable limit of error for that load.

Interpretation of Results (Creep - Return-to-Zero) • The deviation on returning to zero as soon as the indication has stabilized shall not exceed 0.5 e. • On multi-interval device, the deviation shall not exceed 0.5 e1 • On a multiple range device, the deviation on returning to zero from Maxi shall not exceed 0.5ei ;

moreover, after returning to zero from any load greater than Max1 and immediately after switching to the lowest weighing range, the indication near zero shall not vary by more than e1 during the following 5 minutes.



Revision Rev. 1 (September 2009)

• Removed requirement for testing at temperatures other than nominal Rev. 2 (March 2010)

• AZSM renamed to AZT • Formatting changes • Procedures adjusted for 30 minute creep test length


Part: 3 Section: 15 LG-3.15 Temperature Effect on the No-Load Indication

LG-3.15 Temperature Effect on the No-Load Indication

Reference Section 24 of the Specifications Relating to Non Automatic Weighing Devices (1998)

Application This test is performed on any complete electronic device, any electronic indicator or weighing element tested separately.

Settings • AZSM and AZT must be turned off or set to zero value. If it is not convenient to do so, a small

weight (i.e. 10 to 20 graduations) may be placed on the platter to bring the indication off the AZT range.


• The test is performed when the environmental chamber's temperature is being changed. The sequence is as follows:

First test: from 20°C (or the mid point of the temperature range if significantly different from

20°C) to -10°C (or the lower point of the temperature range marked on the device);

Second test: from - 10°C to + 40°C (or the higher point of the temperature range marked on t he device);

Third test: from + 40°C to 20°C (or the mid point of the temperature range marked on the

device);

• The temperature of the DUT must have stabilized to within ± 1°C.


• Moisture content in the environmental chamber must not exceed ≈ 50% RH at test temperatures. • The test equipment such as load cell simulators, high precision reference indicators, must be

isolated from the test conditions and maintained at constant ambient temperature and humidity. • The temperature in the chamber is changed at a rate not to exceed 1°C per minute. • If so equipped, the "enhance resolution feature" of the device will be used during the tests. If this

feature is not available, use the error weight method to determine the device errors before rounding.

Procedure 1. Stabilize the DUT at no load condition and at the start temperature for a period of time equal to the

time that was required to apply an remove the load during the previous test.


Part: 3 Section: 15 LG-3.15 Temperature Effect on the No-Load Indication

2. Zero the DUT, if the AZT is disabled; or place a small load ( ±5 e) on the platter, and record the registration (Determine the error before rounding using small denomination weights).

3. From 20°C to -10°C Lower the temperature of the environmental chamber down to -10°C at a rate

not to exceed 1°C per minute.

4. When the DUT has reached temperature stability, wait an additional 2 hours.

5. If an enhanced resolution feature is being used then record the registration. Otherwise, using small denomination weights determine and record the registration prior to rounding. Record the results.

6. From -10°C to 40°C Increase the temperature of the environmental chamber up to 40°C at a rate

not to exceed 1°C per minute.


8. If an enhanced resolution feature is being used then record the registration. Otherwise, Using small denomination weights determine and record the registration prior to rounding. Record the results.

9. From 40°C to 20°C Decrease the temperature of the environmental chamber to 20°C at a rate not

to exceed 1°C per minute.


11. Using small denomination weights determine and record the registration prior to rounding. Record the results.

Interpretation of Results The device meets the requirements if the indication at zero or near zero does not vary by more than:

• one verification scale interval e per 1°C change in temperature, for Class I devices; • three verification scale intervals e per 5°C change in temperature, for Class III HD devices; and • one verification scale interval e per 5°C change in temperature, for all other device classes.


• AZSM renamed to AZTM • IZSM requirements altered • Added requirement for testing between 40°C and 20°C


Part: 3 Section: 16 LG-3.16 Damp heat, Steady State

LG-3.16 Damp heat, Steady State


Application This test is intended for any complete electronic weighing devices, and for any electronic weighing elements or electronic indicating elements tested separately. The test consists of exposure of the DUT to a constant temperature and constant relative humidity. Note: The damp heat steady state test is not presently performed by the Laboratory. MC intends to

implement this test in the future.


selectable value, it will be set to zero. The amount that the AZT may track at once can not exceed 0.6 e which is the maximum value allowed by the Specifications.

• If a device is provided with an IZSM, the tests will be performed once with the IZSM set to the

maximum of its range.

• The weighing device must be leveled to its reference position, be adjusted as close as possible to zero error at ≈ 20°C (or the mid point of the temperature range marked on the device, if significantly different from 20°C) after it has reached thermal equilibrium with power applied. Except for zero-setting, the device must not be adjusted or re-adjusted at any time during the test.




• When the environmental chamber has reached the desire temperature, allow a minimum of 3

hours for the temperature of the DUT to stabilize.


• The test equipment such as load cell simulators, high precision reference indicators, must be

isolated from the test conditions and maintained at constant ambient temperature and humidity.

• This test is performed following the series of temperature test described in LG-3.13. The first test (≈ 20°C/50% RH) described below is in fact the last test in the series of temperature test. See the Recommended Test Sequence.


Part: 3 Section: 16 LG-3.16 Damp heat, Steady State

Procedure

At ≈ 20° C/50% RH 1. Condition the device. Record the temperature and humidity rate.

2. Perform a minimum of three increasing and decreasing load test and record the results.

At 40°C/85% RH 1. Increase the temperature of the chamber and raise the humidity rate.

2. Condition the device.

3. When the device has reached temperature and humidity stability, allow for 48 hours. The

temperature and humidity rate must remain constant.

4. Then perform a minimum of three increasing and decreasing load tests. Record the results.

At 20°C/50% RH 1. Condition the device. Record the temperature and humidity rate.

2. Perform a minimum of three increasing and decreasing load test and record the results.

Interpretation of Results The device meets the requirements if under the above conditions it performs within applicable limits of error. For more details concerning the procedure, see OIML R 76-1.


• AZSM renamed to AZTM • formatting change


Part: 3 Section: 17 LG-3.17 Electromagnetic Discharge Test

LG-3.17 Electromagnetic Discharge Test

Reference None

Application This test is intended for any complete electronic weighing devices and for any electronic major elements tested separately.

Settings and procedure For more details concerning the procedure, see OIML R 76-1. Note: The electrostatic discharge test is not presently performed by the Laboratory. MC intends to




Part: 3 Section: 18 LG-3.18 Short Time Power Reduction Test

LG-3.18 Short Time Power Reduction Test

Reference None






Part: 3 Section: 19 LG-3.19 Burst Test

LG-3.19 Burst Test

Reference None






Part: 3 Section: 20 LG-3.20 Endurance (Permanence) Test

LG-3.20 Endurance (Permanence) Test

Reference Sections 9, 10, 11, 12, 13, 14, 15, 16, and 21 of the Specifications Relating to Non Automatic Weighing Devices (1998)

Application This test is intended for any complete mechanical or electronic weighing devices and for any weighing elements tested separately. Devices are subjected to the repetitive loading and unloading of specific loads applied 100 000 times (capacities of up to 1 000 kg (2 000 lb)) or 300 times (capacities above 1 000 kg (2 000 lb)). The endurance test is performed after all other tests.


selectable value, it will be set to zero. The amount that the AZT may track at once may not be set to a value larger than 0.6 e which is the maximum value allowed by the Specifications.

• If a device is provided with an IZSM, the test will be performed only once with the IZSM set at the upper limit of its range.

• The weighing device must be leveled to its reference position, be adjusted as close as possible to zero error, and pre-loaded to the maximum capacity at least once.


• If so equipped, the "enhance resolution feature" of the device will be used during the test. If this feature is not available, use the small weight method to determine the device errors before rounding.

• This test is performed at ambient temperature (≈ 20°C); or at the mid point of the temperature range if significantly different from 20°C.

Procedure (capacities of up to 1 000 kg (2 000 lb)) The following test load shall be used: Devices with Max ≤ 100 kg: Load equal to ½ Max; Devices with Max > 100 kg: Load between ¼ and ½ of Max without exceeding 250 kg.

1. After having moved the device to the permanence testing bench, perform the test described in LG-3.21.

2. Apply the test load 25 000 times; perform an increasing and decreasing load test and record the results.

3. Apply the test load an additional 25 000 times; perform an increasing and decreasing load test and record the results.

4. Apply the test load an additional 25 000 times; perform an increasing and decreasing load test and record the results.

5. Apply the test load an additional 25 000 times. 6. Perform a load discrimination test, an increasing and decreasing load test, an eccentricity test. 7. Record the results.

Procedure (capacities above 1 000 kg (2 000 lb)) The following test load shall be used:


Part: 3 Section: 20 LG-3.20 Endurance (Permanence) Test

Load between ¼ and ½ of Max

1. After having moved the device to the permanence testing area, perform an increasing and decreasing test to ascertain that the device measures as close to zero error as possible. Re-calibrate the DUT as necessary.

2. Apply the test load 300 times; perform an increasing and decreasing load test and record the results.

3. Perform a load discrimination test, an increasing and decreasing load test, an eccentricity test. 4. Record the results.

Procedure (For devices tested in the field)

1. After having moved the device to the permanence testing area, perform an increasing and decreasing test to ascertain that the device measures as close to zero error as possible. Re-calibrate the DUT as necessary.

2. Ensure that the device is sealed or that the audit trail is active so the device cannot be re-calibrated.

3. The applicant is to provide proof that the required number of weighings (300 or 100,000) has been completed

4. Perform an increasing and decreasing load test and record the results. 5. Perform a load discrimination test, an increasing and decreasing load test, an eccentricity test. 6. Record the results.

Interpretation of Results The device meets the requirements if all the results remain within the applicable limits of error.

Revision Rev.1 (September 2009)

• Procedure added for 300 weighings for devices with a capacity greater than 1000 kg Rev. 2 (March 2010)

• AZSM renamed to AZT • IZSM requirements altered • Test procedure altered to reference LG-3.21


Part: 3 Section: 21 LG-3.21 Portability Test

LG-3.21 Portability Test

Reference Sections 9, 10, 11, 12, 22 and 30 of the Specifications Relating to Non Automatic Weighing Devices (1998)

Application This test is intended for any device. For portable device this test must be performed at least once, after moving the device to the temperature chamber or to the permanence testing area, and should be performed whenever the device is moved during performance testing. For devices intended for permanent installation this test must be performed whenever the device is moved during performance testing.


selectable value, it will be set to zero. The amount that the AZT may track at once may not be set to a value larger than 0.6 e which is the maximum value allowed by the Specifications.

• The weighing device must be leveled to its reference position, and pre-loaded to the maximum capacity at least once.


• If so equipped, the "enhance resolution feature" of the device will be used during the test. If this feature is not available, use the small weight method to determine the device errors before rounding.

• This test is performed at ambient temperature (≈ 20°C); or at the mid point of the temperature range if significantly different from 20°C.

Procedure 1. After having moved the device, perform an increasing and decreasing test.


For portable devices: The device meets the requirements if all the results remain within the applicable limits of error. If the error curve of the device has been significantly altered, but still within tolerance, then the device may be re-calibrated.

For permanent devices: If the error curve of the device has been significantly altered then the device may be re-calibrated, even if the results are not within the applicable limits of error.


Laboratory Manual - Non Automatic Weighing Devices...Weighing devices and major components are...

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