ME2308_LML Mm Lab

http://www.francisxavier.ac.in

FRANCIS XAVIER ENGINEERING COLLEGE

An NBA ACCREDITED COLLEGE

Recognized under section 2(f) of the UGC Act, 1956

TIRUNELVELI

DEPARTMENT OF MECHANICAL ENGINEERING

V SEMESTER

REGULATION 2008

ME 2308 METROLOGY & MEASUREMENTS

LAB MANUAL

Prepared & Compiled by

G.V.Vigneshwaran., ME.,

Laboratory In Charge

Department of Mechanical Engineering

http://www.francisxavier.ac.in 2

INDEX

Ex.

No NAME OF THE EXPERIMENT Page No.

1 INTRODUCTION TO METROLOGY

2 COMPARISON AND MEASUREMENTS USING VERNIER

CALIPER AND MICROMETER

3 CALIBRATION OF VERNIER CALIPER USING SLIP GAUGE

4 CALIBRATION OF MICROMETER USING SLIP GAUGE

5 COMPARISON AND MEASUREMENTS USING VERNIER

HEIGHT GAUGE AND VERNIER DEPTH GAUGE

6 MEASUREMENT OF GEAR PARAMETERS USING GEAR

TOOTH VERNIER

7 TAPER ANGLE MEASUREMENT USING SINE BAR AND SLIP

GAUGE

8 MEASUREMENT OF ANGLE USING VERNIER BEVEL

PROTRACTOR

9 MEASUREMENT OF DIMENTION OF GIVEN SPECIMEN

USING TOOL MAKERS MICROSCOPE

10 MEASURMENT OF THREAD PARAMETER USING PROFILE

PROJECTOR

11 MEASUREMENT OF VIBRATION PARAMETERS USING

VIBRATION SET UP

12 MEASUREMENT OF DISPLACEMENT USING LVDT

13 MEASUREMENT OF THREAD PARAMETERS BY USING

FLOATING CARRIAGE MICROMETER

14 MEASUREMENT OF TORQUE USING STRAIN GAUGE

15 TEMPERATURE MEASUREMENT BY USING

THERMOCOUPLE

16 CHECKING THE DIMENSIONS OF COMPONENT USING

MECHANICAL COMPARATOR


------------------------------------------------------------------------------------------------ INTRODUCTION TO METROLOGY

------------------------------------------------------------------------------------------------ Ex.No. 1 Date:

AIM To study about the basics of the engineering metrology and measurements.

FUNDAMENTALS

METROLOGY

Metrology is a Science of measurement . The most important parameter in

metrology is the length. Metrology is divided into Industrial Metrology and Medical

Metrology under consideration of its application and may be divided into metrology of length

and Metrology of time under consideration of its quantity. Metrology is mainly concerned

with the following aspects

Unit of measurement and their standards.

Errors of measurement. Changing the units in the form of standards.

Ensuring the uniformity of measurements. New methods of measurement developing. Analyzing this new methods and their accuracy.

Establishing uncertainty of measurement. Gauges designing, manufacturing and testing.

Researching the causes of measuring errors. Industrial Inspection.

FUNCTIONS OF METROLOGY

To ensure conservation of national standards.

Guarantee their accuracy by comparison with international standards. To organise training in this field. Take part in the work of other National Organization.

To impart proper accuracy to the secondary standards. Carry out Scientific and Technical work in the field of measurement.

Regulate, supervise and control the manufacturer. Giving advice to repair of measuring instruments. To inspect and to detect guilty of measurement.

APPLICATIONS OF METROLOGY

Industrial Measurement Commercial transactions Public health and human safety ensuring.


NEED OF INSPECTION

To determine the fitness of new made materials, products or component part and to

compare the materials, products to the established standard. It is summarised as

To conforming the materials or products to the standard. To avoid faulty product coming out. To maintain the good relationship between customer and manufacturer.

To meet the interchangeability of manufacturer. To maintain the good quality.

To take decision on the defective parts. To purchase good quality raw materials. To reduce the scrap.

BASIC CONCEPTS OF MEASUREMENTS

Measurement is the outcome of an opinion formed by observers about some physical quantity.

Measurement is an essential part of the development of technology.

Measurement is a complex of operations carried out by means of measuring instruments.

ELEMENTS OF A MEASUREMENT

Measurand: It is a physical quantity or property (length, diameter, thickness, angle etc.).

Reference : Reference is a physical quantity or property and comparisons are made by them.

Comparator: Comparing measurand with some other reference.

NEED FOR MEASUREMENT

To determine the true dimensions of a part. To increase our knowledge and understanding of the world.

Needed for ensuring public health and human safety. To convert physical parameters into meaningful numbers. To test if the elements that constitute the system function as per the design.

For evaluating the performance of a system. For studying some basic laws of nature.

To ensure interchangeability with a view to promoting mass production. To evaluate the response of the system to a particular point. Check the limitations of theory in actual situation.

To establish the validity of design and for finding new data and new designs.

METHODS OF MEASUREMENT

1. Direct comparison with Primary or Secondary Standard.

2. Indirect comparison with a standard through calibration system.

3. Comparative method.

4. Coincidence method.


5. Fundamental method.

6. Contact method.

7. Transposition method.

8. Complementary method.

9. Deflection method.

1) Direct method:

The value to be measured is directly obtained. Examples: Vernier calipers, Scales.

2) Indirect method:

The value of quantity to be measured is obtained by measuring other quantities.

Diameter measurement by using three wires.

3) Comparative method:

In this method, the quantity to be measured is compared with other known value.

Example:Comparators.

4) Coincidence method:

The value of the quantity to be measured and determined is coincide with certain lines

and signals.

5) Fundamental method:

Measuring a quantity directly in related with the definition of that quantity

6) Contact method:

The sensor or measuring tip of the instrument touches the area (or) diameter (or)

surface to be measured. Example: Vernier caliper.

7) Transposition method:

In this method, the quantity to be measured is first balanced by a known value and

then it is balanced by other new known value. Example: Determination of mass by balancing

methods.

8) Complementary method:

The value of quantity to be measured is combined with known value of the same

quantity. Example: Volume determination by liquid displacement.

9) Deflection method:

The value to be measured is directly indicated by a deflection of pointer. Example: Pr

measurement.

RESULT

Thus the basics of the engineering metrology and measurements were studied.


------------------------------------------------------------------------------------ COMPARISON AND MEASUREMENTS USING VERNIER CALIPER AND

MICROMETER

------------------------------------------------------------------------------------ Ex.No. 2 Date:

AIM

To determine the diameter of the given specimen by using the precision measuring

instruments like Vernier caliper, Micrometer and comparing the results.

APPARATUS REQUIRED

1. Surface plate,

2. Vernier caliper,

3. Micrometer.

SPECIFICATION

Vernier caliper Range: L. C:

Micrometer Range: L. C:

FORMULAE

VERNIER CALIPER

Least Count = 1 Main Scale Division Vernier Scale Division

Vernier Scale Reading = Vernier Scale Coincidence X Least Count

Total Reading = Main Scale Reading + Vernier Scale Reading

MICROMETER

Pitch Scale Reading = Pitch Scale Coincidence x Least Count

Total Reading = Head Scale Reading + Pitch Scale Reading

STUDY

SURFACE PLATE

The foundation of all geometric accuracy and indeed of all dimensional measurement

in workshop is surface plate. It is a flat smooth surface sometimes with leveling screws at the

bottom.

Uses:

It is used as a base in all measurements.


VERNIER CALIPER

The Vernier caliper has one L shaped frame with a fixed jaw on which Vernier scale

is attached. The principle of Vernier is that when two scale divisions slightly different in sizes

can be used to measure the length very accurately.

Least Count is the smallest length that can be measured accurately and is equal to the

difference between a main scale division and a Vernier scale division.

Uses:

It is used to measure the external diameter, the internal diameter and the length of the

given specimen.

Fig. Vernier Caliper

MICROMETER

The micrometer has an accurate screw having about 10 to 20 threads/cm and revolves

in a fixed nut. The end of the screw is one tip and the other is constructed by a stationary

anvil.

Fig. Micrometer


Uses:

Outside micrometer is used to measure the diameter of solid cylinder.

Inside micrometer is used to measure the internal diameters of hollow cylinders and

spheres.

PROCEDURE FOR CALIBRATION

1. Range of the instruments is noted down.

2. The measuring instrument is placed on the surface plate and set for zero

3. Vernier is checked for zero error

4. Work piece is clamped between the jaws and the vernier scale is tighten by screws

5. Main scale and vernier scale coincidence are noted for 5 times and tabulated

6. Micrometer is checked for zero error

7. Work piece is clamped and its head scale reading and pitch scale coincidence is

noted and tabulated

8. The two averages are calculated and the difference is determined

TABULATION

VERNIER CALIPER

Least count = 0.02 mm

S.No.

Main Scale

Reading

(MSR)

in mm

Vernier Scale

Coincidence

(VSC)

Vernier Scale Reading

(VSR) = VSC x LC

in mm

Total Reading

= MSR + VSR

in mm

1

2

3

4

5


MICROMETER


S.No.

Head Scale

Reading

(HSR)

in mm

Pitch Scale

Coincidence

(PSC)

Pitch Scale Reading (PSR)

= PSC x LC

in mm

Total Reading

= HSR + PSR

in mm

1

2

3

4

5

RESULT

The precision measuring instruments are studied and compared. The diameter of work pieces are determined by using

Vernier Caliper = _____________mm Micrometer = ______________ mm


------------------------------------------------------------------------------------ CALIBRATION OF VERNIER CALIPER USING SLIP GAUGE

------------------------------------------------------------------------------------ Ex.No. 3 Date:

AIM To calibrate the given Vernier Caliper using Slip Gauge

APPARATUS REQUIRED

1. Surface Plate, 2. Vernier scale, 3. Slip Gauge.

SPECIFICATION

Vernier caliper Range: L. C:

FORMULAE

Least Count = 1 Main Scale Division 1 Vernier Scale Division



Error = Slip gauge reading - Total reading

% Error = x 100

STUDY

SURFACE PLATE



bottom.

Uses:


VERNIER CALIPER

The Vernier caliper has one L shaped frame with a fixed jaw on which Vernier scale

is attached. The principle of Vernier is that when two scale divisions slightly different in sizes

can be used to measure the length very accurately.

Least Count is the smallest length that can be measured accurately and is equal to the

difference between a main scale division and a Vernier scale division.

Uses:

It is used to measure the external diameter, the internal diameter and the length of the

given specimen.

Error

Actual reading


Fig. Vernier Caliper

SLIP GAUGES

They are rectangular blocks hardened and carefully stabilized. The surfaces are highly

polished to enhance wringing. It is used as a reference standard for transferring the dimensions of unit of length from primary standard. It is generally made up of high carbon,

high chromium hardened steel. Uses:

These are accurate and used as comparator.

Fig. Set of Slip Gauges




2. Clean the Vernier calipers fixed and movable jaws and slip gauges to be

measured with a fine cotton cloth

3. Vernier is checked for zero error

4. Slip gauge is clamped between the jaws and the vernier scale is tighten by screws

5. Main scale and vernier scale coincidence are noted for 5 different slip gauges

6. Calculate the error and percentage error

7. Plot the graph between

(i) Slip gauge reading vs Total reading (Vernier caliper)

(ii) Slip gauge reading vs Error

TABULATION

Least count of Vernier caliper = 0.02 mm

S.

No.

Slip

Gauge

Reading

Vernier caliper Reading Error % of

Error

MSR VSC VSR = VSC

x LC

TR =

(MSR+VSR)

1

2

3

4

5


MODEL GRAPH

RESULT

Thus the Vernier caliper was calibrated using slip gauges Error range = ____________ mm


------------------------------------------------------------------------------------ CALIBRATION OF MICROMETER USING SLIP GAUGE

------------------------------------------------------------------------------------ Ex.No. 4 Date:

Aim: To calibrate the given Micrometer using Slip Gauge.

Apparatus Required:

4. Surface Plate, 5. Vernier scale, 6. Slip Gauge.

SPECIFICATION

Micrometer Range: L. C:

FORMULAE

Least Count = Pitch Scale Division / Number of Threads

Pitch Scale Division = Distance Moved / Number of Rotation

Pitch Scale Reading = Pitch Scale Coincidence x Least Count

Total Reading = Head Scale Reading + Pitch Scale Reading

Error = Slip gauge reading - Total reading

% Error = x 100

STUDY

SURFACE PLATE



bottom.

Uses:


MICROMETER

The micrometer has an accurate screw having about 10 to 20 threads/cm and revolves

in a fixed nut. The end of the screw is one tip and the other is constructed by a stationary

anvil.

Uses:

Outside micrometer is used to measure the diameter of solid cylinder.

Inside micrometer is used to measure the internal diameters of hollow cylinders and

spheres.

Error

Actual reading


Fig. Micrometer

SLIP GAUGES They are rectangular blocks hardened and carefully stabilized. The surfaces are highly

polished to enhance wringing. It is used as a reference standard for transferring the dimensions of unit of length from primary standard. It is generally made up of high carbon,

high chromium hardened steel. Uses:






2. Clean the Micrometers anvil, spindle and slip gauges to be measured with a fine

cotton cloth

3. Micrometer is checked for zero error

4. Slip gauge is clamped between the anvil and spindle by using friction or ratchet drive

5. Head scale reading and Pitch scale coincidence are noted for 5 different slip gauges

6. Calculate the error and percentage error

7. Plot the graph between

(i) Slip gauge reading vs Total reading (Micrometer)

(ii) Slip gauge reading vs Error

TABULATION

Least count of Micrometer = 0.01 mm

S.

No.

Slip

Gauge

Reading

Micrometer Reading Error % of

Error

HSR PSC PSR = PSC x

LC

TR =

(HSR+PSR)

1

2

3

4

5


MODEL GRAPH

RESULT

Thus the micrometer was calibrated using slip gauges Error range = ____________ mm


------------------------------------------------------------------------------------ COMPARISON AND MEASUREMENTS USING VERNIER HEIGHT GAUGE AND

VERNIER DEPTH GAUGE

------------------------------------------------------------------------------------ Ex.No. 5 Date:

AIM

To determine the height of the given specimen by using the precision measuring

instruments like Vernier height gauge and Vernier depth gauge and comparing the results.

APPARATUS REQUIRED

1. Surface plate,

2. Vernier caliper,

3. Micrometer.

SPECIFICATION

Vernier height gauge Range: L. C:

Vernier depth gauge Range: L. C:

FORMULAE

VERNIER HEIGHT GAUGE




VERNIER DEPTH GAUGE




STUDY

SURFACE PLATE



bottom.

Uses:



Fig. Surface Plate


A removable clamp is attached between the measuring jaws and vernier. Both the

upper and lower end of measuring jaws are parallel to the base of vernier height gauge. A

scribbling attachement is fitted to mark scribe lines on the parts, where it is required. The

surface of surface plate is a datum or reference while doing measurement by using any other

measuring instruments.

Fig. Vernier height gauge


Uses:

It is used to measure the heigth of the given specimen.

VERNIER DEPTH GAUGE

The graduated scale is directly slide through the base, but the vernier scale remains

stationary. The base and the anvil should be firmly rested on the surface of the part to be

measured. If it is not so, the base may be affected by a trifle effected when the applied force

increases.

Fig. Vernier depth gauge

Uses:

Used for measuring the depth of holes, recesses and distance from a plane.


1. Clean the main scale, vernier scale and measuring jaws of the vernier height gauge

and vernier depth gauge with fine cotton cloth

2. The vernier height gauge is checked for zero

3. Place the job in the surface plate

4. Place the measuring jaw such that it touches the surface to be measured from the

smooth surface

5. Measure the main scale reading and vernier scale coincidence of the vernier height

gauge

6. The vernier depth gauge is checked for zero error

7. Place the job in the surface plate


8. Place the measuring face such that it touches the surface to be measured from the

smooth surface

9. Measure the main scale resding and vernier scale coincidence of the vernier depth

gauge

TABULATION



S.No.

Main Scale

Reading

(MSR)

in mm

Vernier Scale

Coincidence

(VSC)


(VSR) = VSC x LC

in mm

Total Reading

= MSR + VSR

in mm

1

2

3

4

5


VERNIER DEPTH GAUGE


S.No.

Main Scale

Reading

(MSR)

in mm

Vernier Scale

Coincidence

(VSC)


(VSR) = VSC x LC

in mm

Total Reading

= MSR + VSR

in mm

1

2

3

4

5

RESULT

The precision measuring instruments are studied and compared. The diameter of work pieces are determined by using

Vernier height gauge = _____________mm

Vernier depth gauge = _____________mm Difference between the two instruments = _____________mm


----------------------------------------------------------------------------------------------------------------

MEASUREMENT OF GEAR PARAMETERS USING GEAR TOOTH VERNIER

----------------------------------------------------------------------------------------------------------------

Ex.No.6 Date:

AIM

To measure gear parameters for the given spur gear by gear tooth Vernier.

APPARATUS REQUIRED

1. Gear tooth Vernier, 2. Gear specimen.

SPECIFICATION

Gear tooth Vernier: Range: Horizontal = 0-40 mm Least count = 0.02 mm Vertical = 0-20 mm

FORMULA

Where, W = Chordal width of tooth in mm m = Module of gear in mm

D = Chordal addendum of gear in mm T = No. of teeth

d = Outside diameter of gear in mm

STUDY

GEAR TOOTH VERNIER

The tooth thickness is defined as the length of the arc of the pitch circle between opposite faces of the same tooth. Most of the time a gear vernier is used to determine the tooth thickness. As the tooth thickness varies from top to bottom, any instrument for

measuring on a single tooth must

1. Measure the tooth thickness at a specified position on the tooth.

2. Fix that position at which the measurement is taken.

The gear tooth vernier, therefore, consists of a vernier caliper for making the measurement M, combined with a vernier depth for setting the dimension h at which the

measurement M is to be affected.


Fig. Gear tooth vernier caliper

Fig. Gear tooth thickness at pitch line


TERMINOLOGY OF SPUR GEAR

Fig. Spur gear

Pitch surface: The surface of the imaginary rolling cylinder (cone, etc.) that the toothed gear

may be considered to replace. Pitch circle: A right section of the pitch surface.

Addendum circle: A circle bounding the ends of the teeth, in a right section of the gear.

Root (or dedendum) circle: The circle bounding the spaces between the teeth, in a right section of the gear.

Addendum: The radial distance between the pitch circle and the addendum circle.

Dedendum: The radial distance between the pitch circle and the root circle.

Clearance: The difference between the dedendum of one gear and the addendum of the mating gear.

Face of a tooth: That part of the tooth surface lying outside the pitch surface. Flank of a tooth: The part of the tooth surface lying inside the pitch surface.

Circular thickness: (also called the tooth thickness) The thickness of the tooth measured on

the pitch circle. It is the length of an arc and not the length of a straight line.

Tooth space: The distance between adjacent teeth measured on the pitch circle.

Backlash: The difference between the circle thickness of one gear and the tooth space of the

mating gear. Circular pitch,p: The width of a tooth and a space, measured on the pitch circle.

Diametral pitch P: The number of teeth of a gear per inch of its pitch diameter. A toothed gear must have an integral number of teeth. The circular pitch, therefore, equals the pitch

circumference divided by the number of teeth. The diametral pitch is, by definition, the number of teeth divided by the pitch diameter.


Module m: Pitch diameter divided by number of teeth. The pitch diameter is usually

specified in inches or millimeters; in the former case the module is the inverse of diametral pitch.

Fillet : The small radius that connects the profile of a tooth to the root circle.

Pinion: The smaller of any pair of mating gears. The larger of the pair is called simply the gear.

Velocity ratio: The ratio of the number of revolutions of the driving (or input) gear to the number of revolutions of the driven (or output) gear, in a unit of time.

Pitch point: The point of tangency of the pitch circles of a pair of mating gears.

Common tangent: The line tangent to the pitch circle at the pitch point.

Line of action: A line normal to a pair of mating tooth profiles at their point of contact.

Path of contact: The path traced by the contact point of a pair of tooth profiles. Pressure angle : The angle between the common normal at the point of tooth contact and

the common tangent to the pitch circles. It is also the angle between the line of action and the common tangent.

Base circle : An imaginary circle used in involute gearing to generate the involutes that form the tooth profiles.

PROCEDURE

1. The T, d of the given gear block are measured. 2. The module m it then calculated.

3. Theoretical values of W and D are computed. 4. Theoretical values of W are set in horizontal Vernier scale of gear tooth Vernier and

corresponding actual D value scale.

5. Theoretical values of D is set and W is measured along Horizontal scale. 6. This procedure is repeated for 5 teeth and value tabulated.

OUTSIDE DIAMETER OF GEAR

Trial Outside diameter d mm

1

2

3

4

5



S.No.

Main Scale

Reading

(MSR)

in mm

Vernier Scale

Coincidence

(VSC)


(VSR) = VSC x LC

in mm

Total Reading =

MSR + VSR

in mm

MEASUREMENT OF ADDENDUM AND CHORDAL WIDTH

Trial Chordal addendum d mm Chordal width w mm

Actual . Theoretical Actual Theoretical

1

2

3

4

5

6

7

Result:

Thus the chordal thickness and addendum of gear are measured using gear tooth Vernier.

The actual values are W =

D =


----------------------------------------------------------------------------------------------------------------

TAPER ANGLE MEASUREMENT USING SINE BAR AND SLIP GAUGE

----------------------------------------------------------------------------------------------------------------

Ex.No.7 Date:

AIM To measure the taper angle of the given specimen using sine bar

APPARATUS REQUIRED

1. Surface plate, 2. Dial gauge with stand, 3. Sine bar,

4. Slip gauge, 5. Specimen.

SPECIFICATION

Sine bar: Range:

FORMULA

Where, = Taper angle h = total height (thickness) of the slip gauges in mm

l = standard length of the sine bar in mm = 200mm

STUDY

SURFACE PLATE



bottom.

Uses:


Fig. Surface Plate


DIAL GAUGE

The dial gauge has got 2 hands. The short hand reads in mm. One complete revolution

of long hand reads one mm. The plunger of the dial gauge has to be placed on the surface whose dimension has to be read.

Least Count = One division of the circular scale with long hand.

Uses:

It is used as a mechanical comparator.

SINEBAR

A sine bar consists of a hardened, precision ground body with two precision ground

cylinders fixed at the ends. The distance between the centers of the cylinders is precisely

controlled, and the top of the bar is parallel to a line through the centers of the two rollers.

The dimension between the two rollers is chosen to be a whole number (for ease of later

calculations) and forms the hypotenuse of a triangle when in use.

When a sine bar is placed on a level surface the top edge will be parallel to that surface. If one roller is raised by a known distance, usually using gauge blocks, then the top

edge of the bar will be tilted by the same amount forming an angle tha t may be calculated by the application of the sine rule. Uses:

It is used for setting up work at various angles for the machining or inspection of parts.


Fig. Sine bar

SLIP GAUGES

They are rectangular blocks hardened and carefully stabilized. The surfaces are highly polished to enhance wringing. It is used as a reference standard for transferring the

dimensions of unit of length from primary standard. It is generally made up of high carbon, high chromium hardened steel.

Uses:




PROCEDURE

1. The taper angle of the specimen is first found out approximately with the help of a

bevel protractor. 2. The sine bar is set at this angle on the surface plate with the help of the slip gauges as

shown in the figure.

3. The specimen is placed on the sine bar so that its top taper surface is parallel to the surface plate.

4. The parallelism is checked and adjusted by increasing or decreasing the height level of the slip gauges, so that there should be no deflection in the long hand of the digital gauge when the spindle of the dial gauge is moved over the specimen surface.

5. The total height (thickness) of the slip gauges is noted down. 6. Trial readings are taken by placing the specimen at different points of the sine bar

surface.

TABULATION

S. No. Sinebar length

in mm Height in mm

Sin

1

2

3


Result:

The taper angle of the given specimen is

Using sine bar =_________________________ degrees


---------------------------------------------------------------------------------------------------------------- MEASUREMENT OF ANGLE USING VERNIER BEVEL PROTRACTOR

----------------------------------------------------------------------------------------------------------------

Ex.No.8 Date:

AIM

To measure the angles of given specimen using bevel protractor.

APPARATUS REQUIRED

1. Surface Plate, 2. Dial Gauge, 3. Slip Gauge,

4. Bevel protractor, 5. Specimen

FORMULA

STUDY

BEVEL PROTRACTOR

A bevel protractor is a graduated circular protractor with one pivoted arm; used for measuring or marking off angles. It is attached with an acute angle attachment. The body is

designed such that its back is flat and no projection is beyond its back. The base plate is attached to the main body and an adjustable blade is attached to the circular plate containing

vernier scale. The main scale is graduated in degrees from 0o-90o in both the direction. The adjustable blade can be made to rotate freely about the centre. The base plate is made flat for measuring angles and can be moved throughtout its length.

Uses:

It has wide application in architectural and mechanical drawing, although its use is

decreasing with the availability of modern drawing software or CAD.

Fig. Bevel Protractor

PROCEDURE 1. Initially bevel protractor is adjusted as per requirements. 2. Specimen is placed between the blades.

3. Reading noted directly from main scale and Vernier scale 4. For measuring, taper angle of sine bar, protractor is fixed to height gauge.


5. The protractor is corresponding adjusted. 6. Noted reading is tabulated.

TABULATIONS

Specimen 1:

S.No.

Main Scale

Reading

(MSR)

in mm

Vernier Scale

Coincidence

(VSC)


(VSR) = VSC x LC

in mm

Total Reading =

MSR + VSR

in mm

Specimen 2:

S.No.

Main Scale

Reading

(MSR)

in mm

Vernier Scale

Coincidence

(VSC)


(VSR) = VSC x LC

in mm

Total Reading =

MSR + VSR

in mm

RESULT:

Thus angle of the given specimens was determined by using bevel protractor

Angle of the given specimen 1 = ______________ Angle of the given specimen 2 = ______________


---------------------------------------------------------------------------------------------------------------- MEASUREMENT OF DIMENTION OF GIVEN SPECIMEN USING

TOOL MAKERS MICROSCOPE

----------------------------------------------------------------------------------------------------------------

Ex.No. 9 Date:

AIM

To measure the pitch &angle of the screw thread.

APPARATUS REQUIRED

1. Tool makers microscope,

2. Screw thread specimen

SPECIFICATION

Magnification : 30x (standard)

Objective : 2x

Eyepiece : w.f.15x with cross rectile

Field of view : 8mm. (approx)

Working distance : 80mm

Observation tube : monocular inclined at 30 degree

Stand : large and heavy base provide extra overall rigidity to the Instrument

Measurement stage : 150x150. size travel up to 50mm in each direction, least count 6

minutes.

STUDY

TOOL-MAKERS MICROSCOPE

Tool makers microscope is based on the Principle of optics. The microscope consists

of a heavy-duty hallow-duty hallow base, which accommodates the illuminating unit underneath, and above this on the top surface of the base, the work table carriage is supported on ball and controlled by micrometer screws. Projecting up from the rear of the base is a

column, which carries the microscope unit and various interchangeable eyepieces. Uses:

The chief applications of the tool room microscope are as follows 1. The determination of relative position of various points on work.

2. Measurement of angle by using a protractor eyepiece.

3. Comparison of thread forms with master profiles engraved in the eyepiece,

measurement of pitch and effective diameter.

CONSTRUCITON OF MICROSCOPE

Base:

The study base rest on three support two of which are adjustable for leveling the

instrument. The base has built in all electrical transformers and their control panel and

transmitted illuminator with green filter.


Arm:

The arm has a groove guide on which the microscope tube is vertically adjusted by

rack and pinion system.

Focussing Mechanism:

The course focusing movement provided in the microscope tube separately. The

coarse motion is knurled knob on both side of the tube and ha as the total travel of 200mm.

Its also lock any position by lever, this movement is characterized by its exceptionally

smooth and accurate precision. The vertical travel or measurement up to 10mm, thickness can

be read by the depth dial gauge. The thickness is being measured with the difference of two

different focusing of object. The least count of gauge is 0.01.

Fig. Tool makers microscope

Eyepiece Protractor

This unique protractor head graduated 0 to 360 degree with adjustable vernier reading

to 6 minutes cross line incorporated in the protractor head rotating in the optical axis of the

microscope the cross line graticule is replaceable with many other measuring graticules.

Measuring Stage

The stage plate is of 150 X 150 mm having very smooth and precise movements in

both axis with special ball racers arrangements. The travel of the stage is 25mm. in both

direction with precise imported micrometer head, least count 0.01 or 0.005mm. The stage has

two T-slots for mounting accessories like rotary stage, center holding device attachment and

V-block etc.


Rotary Stage

A rotating stage is fixed in T-slots of square plate having 360 degree graduations on

its periphery with vernier reading to6 minute, and lock screw. All types of horizontal angular

measurements can be done with this stage.

Illuminating System

Two possible range of illuminating system are provided with standard equipment to

meet every application, operated through 6 volts solid state variable light control built in

transformer.

1. Sub-stage transmitted light from a bottom source providing collimated green filter

halogen light for viewing contours and transparent objects.

2. Surface incident illuminator for shadow free lighting, for high power examination of

opaque objects.

PROCEDURE

Measurement of screw thread pitch :

1. The image of the thread profile is set so that some of the profile coincides with the

cross hair as seen on the ground-glass screen.

2. The reading on thimble of the longitudinal micrometer screw is noted down.

3. Then the part is traversed by the micrometer screw until a corresponding point on the

profile of the next thread coincides with the cross hairs.

4. The reading on thimble is again noted and the difference in two readings gives the

actual pitch of the screw.

TABULATION

Pitch of the thread:

S.No.

Initial micrometer

reading on thread pitch A (mm)

Final micrometer

reading on thread pitch B (mm)

Pitch of the thread = B-A (mm)

Measurement of angle of thread :

1. It is determined by rotating the screen until a line on the screen coincides with one

flank of the thread profile

2. The angle of screen rotation is noted and then the screen is further rotated till the

same line coincides with the other flank of thread.

3. The difference in two angular readings gives the actual angel of thread on the

screw.


TABULATION

Flank angle of the thread:

S.No. Initial flank angle A

(deg)

Final flank angle B

(deg)

Flank angle

= B-A (deg)

PRECAUTIONS

1. The coincidence on the component & cross hairs must be carefully matched.

2. Eyepieces are to be handled carefully.

3. Dont expose eyes directly to the light source.

RESULT: The pitch and flank angle of the given object is measured with toolmakers microscope are tabulated.


----------------------------------------------------------------------------------------------------------------

MEASURMENT OF THREAD PARAMETER USING PROFILE PROJECTOR

----------------------------------------------------------------------------------------------------------------

Ex.No. 10 Date:

AIM

To measure thread parameter of a given screw thread using profile projector.

APPARATUS REQUIRED

1. Contour projector 2. Work holding centre

SPECIFICATION

Contour projector magnification accuracy = 0.1%

Micrometer Head = 0-25 mm Least Count = 0.1 mm Colour illuminator = 150/250 W Halogen

Magnification = 10x, 20x, 50x lenses PARTS TO BE MEASURED

Major and Minor diameter Depth and pitch of thread

PROCEDURE

1. The required Magnification adapter is fixed in the center projector.

2. The flat specimen is placed on the glass plate and perfectly focused on the screen. 3. The profile of specimen is traced on a tracing paper is fixed on the screen using

pencil.

4. Then the angle between the two reference surface and dimension are measured using table micrometer and the Rota table screen circular scale and are tabulated

STUDY

PROFILE PROJECTOR

A profile projector is also referred to as an optical comparator, or even known as a

shadowgraph, a profile projector is an optical instrument utilized for measuring. The projector magnifies the profile of the specimen, and shows this on the built- in projection screen. From this screen there is usually a grid that could be rotated 360 degrees therefore the

X-Y axis of the screen could be aligned correctly using a straight edge of the machined part to analyze or measure. This projection screen shows the profile of the sample and is zoomed

for better ease of computing linear dimensions. An edge of the sample to analyze could be aligned using the grid on the screen. After that, basic measurements could be obtained for distances along with other points. This is

being carried out on a zoomed profile of the specimen. It could be easier and also lessen mistakes by measuring on the magnified projection screen of a profile projector.

The conventional way of illumination is by diascopic illumination, and that is illumination from behind. This kind of illumination is also known as transmitted illumination when the sample is transparent and light can go through it. When the specimen is solid, then

the light wont go through it, but can form a profile of the sample. Measuring of the sample can be achieved on the projection screen. A profile projector could also have episcopic

illumination which happens to be light shining from above. This is convenient in exhibiting bores or inner areas that needs to be measured.


Fig. Profile Projector

TABULATION

S.No. Major diameter

D1

(mm)

Minor diameter D2

(mm)

Pitch

(mm)

Angle

(deg)

Depth

(mm)

RESULT

Thus the thread parameter of the given screw thread was found using the pro file

projector.

Major diameter = _______________ mm

Minor diameter = _______________ mm

Pitch of screw = ________________ mm

Depth of thread = ________________ mm

Angle of thread = ________________ mm


----------------------------------------------------------------------------------------------------------------

MEASUREMENT OF VIBRATION PARAMETERS USING VIBRATION SET UP

----------------------------------------------------------------------------------------------------------------

Ex.No.11 Date:

AIM

To study the various parameters involved in the vibrations of a given system.

To plot the characteristic curves of the given specimen

APPARATUS REQUIRED

1. Vibration exciter 2. Vibration pick-up

3. Vibration analyzer 4. Power amplifier

5. Oscillator

DESCRIPTION

The mechanical vibration, if not within limits may cause damage to the materials, structures associated with it. Vibration exciter is an electrodynamic device. It consists of a

powerful magnet placed centrally surrounding which is suspended the exciter coil. This assembly is enclosed by a high permeability magnetic circuit. When an electrical current is passed through the exciter coil, a magnetic field is created around the coil resulting in the

upward or downward movement of the suspended coil depending upon the direction of the current flow in the coil. Thus controlling the frequency of the coil current, the frequency of

vibration is controlled. Power amplifier is the control unit for the exciter. Piezo electric crystals produce an emf when they are deformed. This output emf

may be measured to know the value of applied force and hence the pressure. A piezo electric material is one in which an electric potential appears across certain

surfaces of a crystal of the dimensions of the crystal are charged by the application of a mechanical force. The effect is reversible. Common piezo electric materials include quartz, Rochelle salt, lithium sulphate etc.,

CAUTION

Do not remove the fuse cap while power chord is connected to 230V AC mains

PROCEDURE

1. Connect power amplifier output to vibration exciter. 2. Place the vibration pick up on vibration exciter spindle.

3. Connect vibration pick up cable to vibration analyzer sensor socket. 4. select the range 0-100 by two way switch. 5. Note down the displacement, velocity and acceleration from vibration analyzer.

6. Similarly noted above parameters in frequency range of 0-1000 Hz.


TABULATION

S.No Frequency (Hz) Displacement (mm) Velocity (cm/sec) Acceleration (m/sec2)

1

2

3

4

5

6

7

8

9

10

Result:

Various parameters of vibration such as displacement, velocity and acceleration are

studied and the following characteristic curves were plotted.

1. Displacement Vs Frequency 2. Velocity Vs Frequency 3. Acceleration Vs Frequency


----------------------------------------------------------------------------------------------------------------

MEASUREMENT OF DISPLACEMENT USING LVDT

----------------------------------------------------------------------------------------------------------------

Ex.No.12 Date:

AIM To measure the displacement using Linear Variable Differential Transformer.

APPARATUS REQUIRED

1. LVDT setup

2. Connecting rode 3. Instrument tutor

STUDY

LVDT

The LVDT converts a position or linear displacement from a mechanical reference (zero, or null position) into a proportional electrical signal containing phase (for direction)

and amplitude (for distance) information. The LVDT operation does not require an electrical contact between the moving part (probe or core assembly) and the coil assembly, but instead relies on electromagnetic coupling.

Uses:

LVDTs have been widely used in applications such as power turbines, hydraulics, automation, aircraft, satellites, nuclear reactors, and many others.

Fig. Linear Variable Differential Transformer.


PROCEDURE

1. Plug the power chard to AC main 230v/50Hz & Switch on the instrument.

2. Plate RED/CAL switch at read position. 3. Balance the amplifier with the help of zero knobs. Without connecting LVDT

to instruments.

4. Replace the RED/CAL switch at CAL position. 5. Adjust the calibration point by rotating CAL knob so display should read 10.00

(i.e.) maximum ranges. 6. Rotate the core of micrometer till the micrometer reads 10 and adjust the

zero potentiometer till the display reads 10

7. Rotate back the micrometer core upto 20.00 and adjust the CAL potentiometer till the display reed 10.00.

8. Now the instrument is calibrated for +/- 10.00 mm range. As the core of LVDT moves the display reads the displacement in mm.

9. Rotate the core of micrometer in steps of 2 mm and tabulate the readings.

10. Plot the graphs between (i) Actual reading Vs Indicator reading,

(ii) Actual reading Vs Error

Actual Micrometer Reading in (mm)

Indicator Reading LVDT

in (mm)

Error % Error

Ascending

2

4

6

8

10

Descending

-2

-4

-6

-8

-10

MODEL GRAPH


RESULT

Thus scale was calibrated using LVDT Linear Variable Differential Transformer.


------------------------------------------------------------------------------------------------ MEASUREMENT OF THREAD PARAMETERS BY USING FLOATING

CARRIAGE MICROMETER

---------------------------------------------------------------------------------------------------------------- Ex.No.13 Date:

AIM

To measure the major diameter, minor diameter & effective diameter of external screw threads by using floating carriage micrometer.

APPARATUS REQUIRED

1. Floating carriage micrometer.

2. Specimen 3. Prism

4. Wire 5. Cylinder.

SPECIFICATIONS

1. Weight of the machine: Approx. 25kg.

2. L x W x H : Approx. 350mm x 150mmx 140mm

3. List count of micrometer : 0.001 mm

4. Standard micrometer or electronic type.

5. Electronic Micrometer has digital display and Std.

6. Dial type Fiducial Indicator with 0.01mm standard dial.

7. Admit between centre 200 mm

8. Max Diameter capacity 100mm

FORMULA

Major Diameter Measurement:

OD = D+ (RS ~ R) Where,

D = Diameter of setting master. RS = Micro meter reading over setting master. R = = Micro meter reading over threaded W/P or gauges, +/ is determined by relative

size of master & work piece.

Minor Diameter Measurement:

ID = D- (R ~ RO) Where,

D = Diameter of setting master. C = Core or minor diameter of work piece. RP = Reading over master & prism

R = Reading over master & prism.

Measurement of effective diameter by using 2 wire method:

E = T+P T= D+ (RW ~ ROW)

Where, E = Effective or pitch diameter.


T = Measured dimension using cylinder. RW= Reading measured over setting master with wire.

ROW= Reading measured over work piece over wire. P = (0.86603 * p) W

W =Mean diameter of cylinder wire used = 1.35 mm p = Pitch of thread = 2 mm

STUDY

FLOATING CARRIAGE MICROMETER

In order to ensure the manufacture of screw threads to the specified limits laid down in the appropriate standard it is essential to provide some means of inspecting the final product. For measurement of internal threads thread plug gauge is used and to check these

plug gauges Floating Carriage Micrometer is used for measuring Major, Minor and Effective diameter.

Measuring machine shown in the figure has Basewith two small and one big adjustable support knobs provided for leveling the assembled unit. Base hastwo parallel integral V grooves one short and other long. Long groove is for guide pegs located at the

bottom of Intermediate Piece or Carriage (B) and smaller for a ball. One more V pair is in the Centre of the base, which is provided for accommodating Centers (E) to hold work

piece. Carriage has two parallel V grooves, one to accommodate two balls and other to accommodate one ball. Underneath the floating top (C) there is one V groove on one side and flat portion on other side. Digital Micrometer is in one bracket (with less width) and dial

type fiducial on the other side lever is provided to tighten it.

Fig. Floating Carriage Micrometer

PROCEDURE

1. The setting master is held b/w center and taken the reading at the diameter say RS

2. The master cylinder is then replaced by a threaded work piece and R is taken. 3. Take the reading on micrometer and indicator in such a way that radius portion of

prism touches master. 4. The cylinder or wire should be chosen so that when placed b/w the threads, they

should contact about halfway down the flanks.


Result:

Thus, the thread parameters of a screw thread are measured using floating carriage micrometer.


------------------------------------------------------------------------------------------------ MEASUREMENT OF TORQUE USING STRAIN GAUGE

------------------------------------------------------------------------------------------------ Ex.No. 14 Date:

AIM

To study the measurement of torque by using reaction torque sensors. APPARATUS REQUIRED

1. Torque measurement equipment 2. Strain gauge

3. Weight 4. Stand 5. Lever

FORMULA

Calculated Torque = Load x Distance (kg-m)

Error = Actual Torque - Normal Torque

STUDY

TORQUE MEASUREMENT

Torque is the tangential force to set a body in rotation. It is represented as a vector of a force for a rigged body undergoing force rotation about a single axis. The equation

relating power to torque is straight forward. A shaft rotating with angular velocity and carrying power will undergo a torque T,

Power = T x Where,

T = Torque. = Angular acceleration.

Thus torque is the essential tensional twisting about its axis of rotation. In this setup shear type load is used to measure the torque an inverse method of measuring the load with the output immune to side load and bending moment is based on measurement of shear

components. The load cell is balancing a beam supported on both ends.

STRAIN GAUGE

A strain gauge takes advantage of the physical property of electrical conductance and its dependence on the conductor's geometry. When an electrical conductor is stretched within

the limits of its elasticity such that it does not break or permanently deform, it will become narrower and longer, changes that increase its electrical resistance end-to-end. Conversely,

when a conductor is compressed such that it does not buckle, it will broaden and shorten, changes that decrease its electrical resistance end-to-end. From the measured electrical resistance of the strain gauge, the amount of applied stress may be inferred.

A typical strain gauge arranges a long, thin conductive strip in a zig-zag pattern of parallel lines such that a small amount of stress in the direction of the orientation of the parallel lines results in a multiplicatively larger strain measurement over the effective length


of the conductor surfaces in the array of conductive linesand hence a multiplicatively larger change in resistancethan would be observed with a single straight-line conductive

wire.

Fig. Strain gauge

PROCEDURE

1. Fix the main frame of transducers rigidity. 2. Connect the cantilever beam with weight pan.

3. Connect transducer wire socket to rear side of indicator. 4. Connect digital indicator at 230V, AC supply. 5. Set zero on indicator, by zero adjust pan provides indicator.

6. Allow the instrument in on position for 10 minutes for initial warm up. 7. Now apply the load gradually and note down reading in upward & downward

trend. 8. Make sure that the capacity of weight added in fulcrum arm should not exceed

1kg.


9. Adjust the potentiometer in the front panel till the display resds 0.00 10. Apply load to the fulcrum arm by adding dead weights in step of 100g.

11. Change the fulcrum distance and repeat the procedure given above. 12. Note down the reading displayed in the instrument LED and tabulate the

readings. 13. Plot the graphs between

(i) Actual reading vs Indicator reading,

(ii) Actual reading vs Error

TABULATIONS

Actual Loading Indicator Reading (kg-m)

Error % Error Distance,

D (m)

Weight, W

(Kg)

D x W

(kg-m)

1 M

0.75 M

0.5 M

0.25 M

MODEL GRAPH

Result:

Thus the torque was determined using various load and distances and the results

tabulated and plotted.

Error range = ______________ kg-m


---------------------------------------------------------------------------------------------------------------- TEMPERATURE MEASUREMENT BY USING THERMOCOUPLE

----------------------------------------------------------------------------------------------------------------

Ex.No. 15 Date:

AIM

To measure the temperature using thermometer and J-type thermocouple apparatus and

to compare the results.

APPARATUS REQUIRED

1. Thermo couple 2. Temperature measuring setup.

3. Thermometer.

FORMULA

Error = Va - Vi

Where,

Va = Actual temperature Vi = Indicated temperature of thermocouple

STUDY

THERMOCOUPLE

The basic principle of thermocouple is when two dissimilar metals are joined

together an e.m.f will exist between the points A and B, which is primarily a function of the

junction temperature. The above principle is called See Back effect.

A thermocouple is a device made by two different wires joined at one end,

called junction end or measuring end. The two wires are called thermoelements or legs of the

thermocouple: the two thermoelements are distnguished as positive and negative ones. The

other end of the thermocouple is called tail end or reference end (Figure1). The junction end

is immersed in the enviroment whose temperature T2 has to be measured, which can be for

instance the temperature of a furnace at about 500C, while the tail end is held at a different

temperature T1, e.g. at ambient temperature.

Fig.:Schematic drawing of a thermocouple

Because of the temperature difference between junction end and tail end a voltage difference can be measured between the two thermoelements at the tail end: so the thermocouple is a temperature-voltage transducer.


PROCEDURE

1. Check the connections made and switch on the instrument by rocker switch at the front panel.

2. Allow the instrument in on position for 10 mins for initial warm up 3. Fill the around full of water to the kettle and place the thermometer and

thermocouple inside the kettle.

4. Note down the initial water temperature from the thermometer. Adjust the initial set potentiometer in the front panel till the display reads initial water temperature.

5. Switch on the kettle and wait till the water boils note down the thermometer reading and final set potentiometer till the display reads boiling water temperature.

6. Remove the thermometer and temperature sensor from the kettle and change the water

and replace the thermocouple and tha thermometer in to kettle. 7. Switch on the kettle and note down the reading for every 10o interval and tabulate the

readings. 8. Plot the graph between

(1) Actual reading Vs Indicator Reading

(2) Actual reading vs Error

TABULATIONS

S.No Actual temperature,

Va in C

Thermocouple indicated temperature,

Vi in C Error % Error

1

2

3

4

5

6

7

8

9

10


MODEL GRAPH

RESULT

Thus the temperature is measured using thermometer and thermocouple apparatus and the comparison was done.

Errror range = _____________C


-------------------------------------------------------------------------------------- --------------------------

CHECKING THE DIMENSIONS OF COMPONENT USING MECHANICAL

COMPARATOR

----------------------------------------------------------------------------------------------------------------

Ex.No. 16 Date:

AIM

To check the height of a mechanical component with standard dimension component

using mechanical comparator

APPARATUS REQUIRED

1) Slip gauge set

2) Mechanical comparator

3) Surface plate

4) Vernier caliper

5) Dial indicator

STUDY

MECHANICAL COMPARATOR

Comparator is one form of linear measurement device which is quick and more

convinent for checking large number of identical dimensions. Comparator normally will not

show the actual dimensions of the work piece. They will be showing only the deviation in

size.

Mechanical comparator employs mechanical terms for magnifying small deviations.

The method of magnification small movements of the indicator in all mechanical comparators

is effected by means of levers gear trains or a combination of these elements. Mechanical

comparators are available having magnifications from 300 to 5000 to 1. These are mostly

used for inspection of small parts machined to closed limits.

Fig. Mechanical Comparator


PROCEDURE

1. Clean the instruments and its accessories by fine cotton cloths

2. Measure the basic size of the given specimen by using Vernier Caliper

3. Place the slip gauge on the mechanical comparator

4. Now set the basic size of the work piece in the mechanical comparator and set the

dial indicator in zero position and remove the slip gauge from the mechanical

comparator

5. The given specimen is placed under the plunger of mechanical comparator and

note down the variation in height of the component is noted from reading of dial.

6. Tabulate the readings

TABULATIONS

Specimen Slip gauge reading

in (mm)

Mechanical

comparator reading

in (mm)

Total value

in (mm)

1

2

RESULT

The dimensions of the specimen was checked by using mechanical comparator.

Actual size of the component = _______________ mm

Deviation from the actual size = _______________ mm

HDR116AHDR116BFigure1

ME2308_LML Mm Lab

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