THERMAL-PULSE FLOVMETER FOR MEASURING SLOW ...THERMAL-PULSE FLOVMETER FOR MEASURING SLOW WATER...
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THERMAL-PULSE FLOVMETER FOR MEASURING SLOW WATER VELOCITIES IN BOREHOLES By A.E. Hess U.S. GEOLOGICAL SURVEY Open-File Report 87-121 Denver, Colorado 1990
Transcript of THERMAL-PULSE FLOVMETER FOR MEASURING SLOW ...THERMAL-PULSE FLOVMETER FOR MEASURING SLOW WATER...
THERMAL-PULSE FLOVMETER FOR MEASURING
SLOW WATER VELOCITIES IN BOREHOLES
By A.E. Hess
U.S. GEOLOGICAL SURVEY
Open-File Report 87-121
Denver, Colorado
1990
DEPARTMENT OF THE INTERIOR
MANUAL LUJAN, JR., Secretary
U.S. Geological Survey
Dallas L. Peck, Director
For additional information write to:
U.S. Geological Survey Mail Stop 403, Box 25046 Denver Federal Center Denver, CO 80225-0046
Copies of this report can be purchased from:
U.S. Geological Survey Books and Open-File Reports Section Denver Federal Center, Bldg. 810 Denver, CO 80225-0046
CONTENTSPage
Abstract 1Introduction 1Thermal-pulse flovmeter system 5
How the system functions 7The probe 9The surface module 9
Operating instructions 10Start-up procedure 10Measurement procedure 11
Calibration and accuracy 13Example of the use of the thermal-pulse flovmeter 17Summary 19References ci ted 20Glossary 22Mechanical details of thermal-pulse flovmeter system 33Electronic details of thermal-pulse flovmeter system 66
FIGURES
Figure 1. U.S. Geological Survey thermal-pulse flovmeter system 22. Functional diagram of U.S. Geological Survey's thermal-pulse
flovmeter system 43. Typical thermal-pulse flovmeter output responses:
(A) upflov response; (B) dovnflov response 54. Operational diagram of thermal-pulse flovmeter system 65. Front and rear vievs of surface module 76. Assembly of thermal flovmeter probe 87. Calibration system for slov velocity flovmeters (modified
from Hess, 1986) 128. Calibration example of a thermal-pulse flovmeter in 2-, 3-,
4-, and 6-inch diameter columns at 25°Celsius 149. Relative zero-flov response in vater as a function of
temperature 1410. Caliper, temperature, and flov velocity logs of URL-10,
modified from Keys (1984) 1611. Acoustic televiever logs of selected depths of URL-10,
modified from Keys (1984) 1612. PN-1, probe connector sub 3313. PN-2, electronics case 3414. PN-3, top centralizer, slide 3515. PN-4, top sensor bulkhead 3616. PN-5, bov spring 3717. PN-6, split ring slide stop; PN-27, connector clamp
screv 3818. PN-9, top fin, 1 5/8 3919. PN-18, bottom fin, 1 5/8 4020. PN-9A, top fin, 2 1/2; PN-18A, bottom fin, 2 1/2 4121. PN-11, thermistor post 4222. PN-12, top flov tube, 1 5/8 4323. PN-12A, top flov tube, 2 1/2 44
111
24. PN-13, heater frame, 1 5/8 4525. PN-13A, heater frame, 2 1/5 4626. PN-15, bottom flow tube, 1 5/8 4727. PN-15A, bottom flow tube, 2 1/2 4828. PN-17, bottom sensor bulkhead 4929. PN-20, bottom cover 5030. PN-21, bottom centralizer slide 5131. PN-22, bottom slide mandrel (1/4 in pipe nipple) (C);
PN-23, 1/4 in pipe cap (C) 5232. PN-26, probe connector carrier 5333. PN-28, heater assembly jig, 1 5/8 5434. PN-28A, heater assembly jig, 2 1/5 5535. PN-30, bulkhead; PN-31, bulkhead 5636. PN-32, printed circuit board mounting block 5737. PN-8, thermister (C); PN-40, 4-pin male connector (C);
PN-47, connect or boot (C) - 5838. PN-44, high-pressure waterproof feedthrough (C) with
mounting detail; PN-45, moulded waterproof connector and cable (C); PN-46, moulded waterproof female connector (C)- 59
39. Electronics carrier assembly, PN-30-30, and 41 6040. Probe electronics layout 6141. PN-42, modification to connector MS3110F10-6S 6242. Assembly of heater (13 or 13A) using heater
assembly jig (28 or 28A) 6343. Assembly of thermistor (8) and post (11) 6444. Assembly of flow sensor tube parts 6545. Schematic of probe electronics, A- and B-boards 6646. A circuit board, probe electronics 6747. B circuit board, probe electronics 6848. Schematic of surface module electronics 6949. Electronic component layout for surface module 70
TABLES
Table 1. Mechanical-parts list for thermal-pulse flowmeter probe 252. Electronic-parts list for thermal-pulse flowmeter probe 273. Electronic-parts list for thermal-pulse flowmeter surface
module 294. Sources of commercial parts used in thermal-pulse flowmeter- 32
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CONVERSION FACTORS
Multiply By To obtain
inch (in.) 25.40 millimeterinch per minute (in./min) 0.4233 millimeter per secondfoot (ft) 0.3048 meterfoot per minute (ft/min) 0.3048 meter per minutegallon per minute (gal/min) 0.06309 liter per second
Degree Fahrenheit (°F) may be converted to degree Celsius (°C) with the following equation:
°C = (5/9)(°F-32)
Degree Celsius (°C) may be converted to degree Fahrenheit (°F) with the following equation:
°F = (9/5)(°C)+32
Other unit abbreviations used in the report are:
microsecond (us) second (s) minute (min) kilohertz (kHz) volt (V)
VERNAL-PULSE FLOVMETER FOR MEASURING SLOV WATER VELOCITIES IN BOREHOLES
By A.E. Hess
ABSTRACT
The U.S. Geological Survey has developed an all electronic, thermal-pulse flowmeter for measuring slow axial-velocities of water in boreholes. The flowmeter has no moving parts, but senses the movement of water (or any other fluid) by a thermal-tag/trace-time technique. In the configuration shown in this report the flowmeter can measure water velocities ranging between about 0.1 to 20 feet per minute, can resolve water velocity differences as small as 0.03 foot per minute, and distinguishes between upward and downward flow. Two diameters of interchangeable flow sensors are described; the smaller sensor is 1.75 inches in diameter including the collapsed centralizer and the larger is 2.75 inches in diameter with collapsed centralizer. The flowmeter probe is 48 inches long and has been tested and used in tubes and boreholes with diameters ranging from 2 to 10 inches. The flowmeter also should be useful in measuring slow velocity flow in larger diameter boreholes, though for best accuracy it should to be calibrated for flow at the diameter of the borehole in which it is to be used. The flowmeter probe has been designed to withstand a water pressure depth of 10,000 feet.
The report includes a description of the operation of the flowmeter, functional diagrams, mechanical drawings, and electronic schematics for both the flowmeter probe and surface electronics. Lists of parts and materials, and instructions for fabrication, assembly, and calibration also are included. These diagrams and lists should be adequate to permit the construction and use of a thermal-pulse flowmeter system by those skilled in machining and fabrication, electronics fabrication, and borehole metrology.
INTRODUCTION
Hydrogeologists commonly use borehole flowmeter logs to obtain profiles of water movement in boreholes under both normal and induced-flow (pumped) conditions to help evaluate the permeability, storage capacity, and other hydrologic properties of the adjacent formations. Most flowmeters can measure flow velocities equal to or faster than 6 ft/min in boreholes with a diameter equal to or larger than 4 in., and some flowmeters have been designed with a stall velocity as slow as 2 ft/min. However, flowmeters that can measure flows much slower than 2 ft/min are needed to adequately characterize the hydrology of many formations studied.
Fluid-tracer techniques have been reported that measure velocities as slow as a few feet per day. Those techniques most commonly used in borehole logging are the radioactive-tracer/gamma-ray detector technique described by Bird and Dempsey (1955) and Edwards and Bolter (1962); and the brine-tracer/ fluid-resistivity detector techniques described by Patten and Bennett (1962) and Keys and MacCary (1971). However, these techniques are slow and tedious, and they can be used only under stringent conditions. Also, the density difference between the injected tracer fluid and the borehole fluid causes uncertainies in the measurement of the slower velocities that may exceed the velocity of the fluid measured.
LOGGING WINCH
BOREHOLE PROBE
1 SURFACE MODULE
THERMAL FLOWMETER USGS MODEL-2
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Figure 1. U.S. Geological Survey thermal-pulse flowmeter system,
Fluid-temperature and fluid-resistivity (or conductivity) logs are useful in locating the entrance and exit of contrasting fluids in a borehole, but they provide little quantitative information relating to the velocity or volume of flow. Gas anemometers and other continuous heat-transfer techniques have been tried for measuring water velocities (Skibitzke 1955, Chapman and Robinson 1962, and Morrow and Kline 1971). Some of these instruments were sensitive to slow flow, but this experimenter determined that the calibration changed so rapidly because of fouling of the sensing surfaces with substances such as mud, lint, gas bubbles, and mineral deposits so that these instruments could not be relied upon as quantitative flowmeters under normal borehole conditions.
A heat-pulse borehole flowmeter was developed by Dudgeon and others (1975) using a thermal-tag/trace-time principle that measures slow velocities while avoiding most of the problems of anemometer-type flowmeters. After evaluating the design of this heat-pulse flowmeter (Hess, 1982), the U.S. Geological Survey developed an improved thermal-pulse flowmeter probe that can operate on a standard four-conductor logging cable in deep boreholes (Hess, 1986). The probe has been designed to withstand water pressure to depths of at least 10,000 ft. Measurements made with the thermal-pulse flowmeter are unaffected by cable length and cable resistance or by electrical ground currents that usually exist in areas that are served by public utility lines. The Survey's thermal-pulse flowmeter system has been designed to be both mechanically rugged and field serviceable. The probe centralizer is an integral part of the flowmeter design, but it may be readily adjusted or reconfigured to suit particular borehole conditions. The surface electronics of the U.S. Geological Survey's flowmeter was built into a double width nuclear instrument module and received its power from a frame that physically supports and powers several modules; although with the addition of a suitable power supply the module could be operated directly from an alternating-current power source, or from a battery. The thermal-pulse flowmeter system consisting of the flowmeter probe, surface module, and clock-driven strip-chart recorder is shown in figure 1.
The thermal-pulse flowmeter described in this report has a useful velocity measuring range in water from about 0.1 to 20 ft/min, and can resolve velocity changes as small as 0.03 ft/min. The flowmeter also distinguishes between upward and downward water movement. The flowmeter probe is about 48 in. long and has two interchangeable flow sensors; the smaller flow sensor has a diameter of about 1.75 in. including the collapsed centralizers, and the larger flow sensor has a diameter of about 2.75 in. including the collapsed centralizers. Thus, the smaller sensor may be used to log the flow in boreholes with diameters of only 2 in. The flowmeter has been tested in tubes and boreholes with diameters ranging from 2 in. to 10 in. It also may be useful for measuring slow, axial flow in larger diameter boreholes, although for best accuracy it should be calibrated for flow at the diameter at which it is to be used. This is because the flowmeter senses only the water velocity in its immediate vicinity rather than the average water velocity over the entire diameter of the borehole and the water velocity in the vicinity of the flowmeter is influenced by the presence of the flowmeter.
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Thermal-tag/trace-time instruments also have been developed by Miller and Small (1982) to measure the velocity of fluids in small diameter tubing, and by Kerfoot (1982) to measure the velocity of water through saturated soil. Tselantis (1984) made a theoretical study of a simplified configuration of the thermal-pulse flowmeter, which he compared to the results of experimental measurements.
THERMAL-PULSE FLOWMETER SYSTEM
A functional diagram of the U.S. Geological Survey's thermal-pulse flowmeter system consisting of the borehole probe, surface module, and clock-driven, strip-chart recorder is shown in figure 2. Water flowing through the hollow sensor section of the probe is thermally tagged by the heat produced by a pulse of electric current in the heater grid. (The heater is an open grid of resistance wire located at the center of the sensor tube.) This heated sheet of water is transported by the water flowing through the sensor tube past one of the two temperature sensors, one located above and the other below the heater grid. The two temperature sensors (thermistors) form two arms of a normally balanced, thermal-electric bridge that becomes unbalanced when the heated sheet of water passes it. This unbalance generates an electrical signal that is transmitted from the probe through the logging cable to the surface module where the signal is recorded on a clock-driven, strip-chart recorder.
Typical flow-response traces are shown in figure 3. The direction of thermal-electric-bridge unbalance is indicative of the direction of water movement. Thus, upward-moving water produces positive-response pulses (fig. 3A), and downward-moving water generally produces negative-response pulses (fig. 3B). The thermal-pulse response time may range from less than 1 s for fast flow to more than 1 min for slow flow.
I I TUpflow Response Peak
TIME
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Figure 3. Typical thermal-pulse flowmeter output responses: (A) upflow response; (B) downflow response.
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How the System Functions
The surface module provides electrical power to the probe, both low voltage for the electronics and high voltage for the heater grid. The surface module also generates the trigger pulse that starts a flow measurement, and then it receives, demodulates, and conditions the flow-response signal from the probe for display on the strip-chart recorder.
A flow-measurement cycle is started by momentarily pressing the CHG/TRIG switch, SI on the front panel of the surface module, from CHG to TRIG (figs. 4 and 5). This sends a negative pulse down logging line 4 to the probe where it is detected and amplified by switch driver U2d,e,f, after passing through a low pass filter consisting of capacitors C3, C4, C5, resistors R7, R8, R9, RIO, and diodes D5 and D6 which separates the trigger pulse from electrical noise and the response pulse-train generated in the probe. The amplified pulse from switch driver U2d,e,f, triggers switch Q3, which discharges capacitor C20 through the heater grid in the flow sensor. The resulting thermal pulse heats a sheet of water that is transported by the flowing water past one of the temperature sensors, upflow sensor Thl or downflow sensor Th2.
A temperature difference between the temperature sensors is converted to a small differential voltage which is amplified by amplifer U4a. The voltage
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Figure 5. Front and rear views of surface module,
NOTE PART NUMBERS FOLLOWED BY AN "A" ARE SELECTED PARTS OF LARGE THERMAL FLOWMETER SENSOR
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FIGURECOMPONENT NAME
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LARGE DIAMETER SENSOR
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THERMAL FLOWMETER PROBE
Figure 6. Assembly of thermal flowmeter probe,
output from U4a modulates the frequency output of voltage-controlled oscillator U3. Water upflow causes this frequency to increase and downflow causes the frequency to decrease. The frequency range of U3 is set for 1 to 35 kHz. The normal no-flow frequency is about 18 kHz. This frequency modulation method is used to avoid ground conducted noise and interference. The circuit consisting of pulse shaper U2a,b,c, and transistors Ql and Q2 shape the output of the voltage controlled oscillator into a train of 10-us long bipolar pulses that are transmitted through the logging cable on line 3 to the surface module.
At the surface module the pulse train is amplified by U3a (fig. 4). The pulse train then travels through pulse shaper Ulb to frequency-to-voltage converter U4, which generates a voltage that is proportional to the frequency of the pulse train and, thus, proportional to the temperature difference between the temperature sensors in the flow sensor. The voltage output from U4 is amplified by operational amplifier U3b and sent to the digital panel meter via HV/FLOW switch S3 and to the strip-chart recorder via the recorder output line. Also added to the recorder output line is an attenuated portion of the pulse heater voltage-pulse from the probe that was transmitted up logging line 1 and through C2. This produces the trigger-time (fig. 3) reference pulse on the recording. The power for the thermal pulse is generated and regulated in the surface module by the adjustable heater-grid circuit consisting of Rll, Tl, Ula,c,b, U2a, U5, and U6.
The Probe
Mechanical drawings of the probe, including both the 1 5/8-in. and the 2 1/2-in.-diameter sensors, are included in figures 12-38 following table 4. Table 1 contains the mechanical parts list. Assembly drawings of the flowmeter probe are shown in figures 6, and 40 through 44. Schematics for the probe electronics are in figure 45, component layout and printed circuit boards (PCB) are shown in figures 46 and 47, relative PCB and pulse capacitor positions are shown in figure 40, and table 2 contains a list of commercially available electronic parts. Table 4 lists the names and addresses of some of the manufacturers from which the Survey obtained some not-to-common parts. The use of company or product names in this report is for identification only and does not constitute an endorsement by the U.S. Geological Survey.
The Surface Module
The power and control circuits in the surface module are contained in a double-wide nuclear-instrument module. The module plugs into and obtains its power from a nuclear-instrument frame. The surface module provides power and control signals for the probe, and it conditions and amplifies the signals from the probe for a recorder. The surface module whose front and rear panels are shown in figure 5 is about 2.7 in. wide, 8.7 in. high, and 10.5 in. deep. Mechanical drawings for the nuclear instrument module are not included because blank nuclear instrument modules are available commercially. A schematic of the surface module electronics is contained in figure 48. A suggested component layout diagram is shown in figure 49, table 3 contains the electronic parts list, and the names and addresses of some of the manufacturers from which the Survey obtained some not too common parts are given in table 4.
OPERATING INSTRUCTIONS
The surface module supplies power to the thermal-pulse flowmeter probe through the logging cable via the multipin INPUT-OUTPUT connector on the rear of the module (fig. 5). The surface module conditions and amplifies the flow-response signal received from the probe and outputs an analog signal to a strip-chart recorder through either the INPUT-OUTPUT connector on the rear of the module or through the test connector labeled REG/TEST on the front of the module. The surface module power switch (S2) is at the top of the front panel. The digital panel meter (DPM), located just below the power switch, displays either the heater voltage (HTR), or the flow-signal imbalance (FLOW) as determined by the position of the HTR/FLOW switch (S3). The CHG/TRIG switch (SI) near the middle of the panel controls the charging and thermal pulsing in the flowmeter probe. The three connectors at the bottom of the front panel are for signal checking. The REG/TEST connector on the lower right is for checking the analog output signal. The flow-signal pulse train, 18 + 17 kHz may be checked at the SIG/TEST connector at the lower center and the heater voltage for the probe heater-grid may be checked at the HTR/TEST connector on the lower left.
Start-up Procedure
1. Connect the flowmeter probe to the logging-cable head, and connect the surface end of the logging cable to the surface module through the INPUT-OUTPUT connector on the rear of the surface module.
2. Place the probe in still water.
3. Connect a strip-chart recorder to the analog output of the surface module through the INPUT-OUTPUT connector located on the rear or to the REG/TEST connector on the front panel, and adjust the recorder sensitivity to 1-V full scale.
4. Use the strip-chart recorder POSITION CONTROL to center the recorder pen (with zero input voltage).
5. Turn the surface module POWER switch on.
6. Switch the HTR/FLOW switch to FLOW.
7. Adjust the DISC control with a screwdriver to its maximum clockwise position. After several minutes warm-up time, the digital panel meter should show a reading between + 20 and the recorder pen should stabilize near the center of the strip chart.
8. Turn the DISC control to the minimum (counter clockwise) position. The recorder pen should go to the negative edge of the strip chart.
9. Turn the DISC control slowly clockwise until the digital panel meter indicates a signal lock-on by a stable reading between + 20; the recorder pen should return to near the center of the strip chart. Turn the DISC control clockwise another 1/4 turn, which should ensure adequate signal for lock-on while rejecting noise.
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10. Flip the CHG/TRIG switch to the TRIG position.
11. Flip the HTR/FLOW switch to HTR; the digital panel meter should read 0, + 1-V.
12. Flip the CHG/TRIG switch to CHG. The digital panel meter now reads the voltage supplied to the pulse-storage capacitors in the probe. Within a 10 s or so the red HTR/RDY light should come on, and the digital panel meter should read 200 + 1-V. The heater voltage may be adjusted with a screwdriver to the proper value by the HTR-ADJ control located just below the HTR side of the HTR/FLOW switch.
If the digital panel meter (and recorder pen) does not respond when the HTR/FLOW switch is in the FLOW position, and there are no steady pulses of at least 5-V peak amplitude at the SIG-TEST connector or 0.1 V on logging line 3, turn the power OFF and recheck all connections. The normal signal frequency on logging line 3 should be about 18 kHz, but it can range from 1 to 35 kHz, depending on the relative imbalance of the thermal-electric bridge in the probe. This bridge will be out of balance when the system is first turned on, and it will take several minutes for it to stabilize. The probe thermistors are very sensitive to small temperature changes, so the sensor section needs to be placed in quiet water (or air) to obtain a stable output response when checking the flowmeter system. Once the flow has stabilized, greater sensitivity to small temperature changes may be realized by increasing the sensitivity of the strip-chart recorder; a switch setting of 0.5 V full scale probably will be adequate for most measurements.
Initially, set the TRIG/ADJ control with a screwdriver to mid position; it may be readjusted during operation to give a trigger reference pulse of adequate amplitude (about 1/4 of full scale) on the chart recording (fig. 3). Adjust the high voltage to 200 V (as read on the digital panel meter) or to the voltage at which the flowmeter was calibrated for the probe sensor in use. The pulse-power capacitors in the probe are fully charged when the red HTR/RDY light is lit.
Measurement Procedure
1. Position the thermal-pulse flowmeter probe sensor in the borehole to the depth desired. The effective plane of measurement is at the center of the flow-sensor tube (fig. 1).
2. Flip the CHG/TRIG switch to CHG. Wait until the red HTR/RDY light has come on and the recorder output has stabilized. This may require 10 min or longer when measuring very slow velocities.
3. Start the strip-chart recorder drive at the desired speed (about 1 in./min for flow velocities of less than 0.3 ft/min and as fast as 100 in./min for flow velocities of 10 ft/min or greater). It may take a few attempts to determine the best chart speed for a given situation.
4. Start a flow-velocity measurement cycle by flipping the CHG/TRIG switch to TRIG. Hold it for a second, until a negative start pulse is recorded on the strip chart and the red HTR/RDY light has gone off, then return the switch to the CHG position.
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V= 24.51 Q/D2 (FEET PER MINUTE)
Q IS FLOW VOLUMEIN GALLONS PER MINUTE
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Figure 7. Calibration system for slow velocity flovmeters (modified from Hess, 1986).
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The HTR/RDY light will remain off indefinitely when the switch is in the TRIG position. The HTR/RDY light should come on 5 to 10 s after the switch is returned to the CHG position, indicating that the pulse capacitors are charged and ready for another flow-measurement cycle.
Normally the sharp, negative trigger start pulse on the strip chart is followed by a slow-forming positive or negative flow-response peak as shown in figure 3. A negative flow-response peak indicates downward flow and a positive flow-response peak usually indicates upward flow. Under certain very slow, down flow conditions, a positive rather than a negative response peak may be formed because of the slight positive buoyancy of the pulse-heated sheet of water.
The flow-response time is measured from the start pulse to the peak of the flow-response pulse. Repeated measurements should be made, allowing adequate time between trigger pulses, until three successive measurements repeat to within a few percent and no longer have a monotonic drift trend. Allow five flow-response time periods or 10 min, whichever is the least, between flow-measurement cycles to permit the heat pulse to dissipate and the flow in the vicinity of the flow sensor to stabilize after each measurement. Thus, a flow-measurement cycle may take from less than 10 s for flow velocities of 10 ft/min or greater, to more than 10 min for flow velocities of 0.3 ft/min or less. The flow rate is determined from the average of the last several measurements. Determine the rate of flow from the flow calibration for the particular flow sensor and borehole diameter involved. Because the strip-chart recorder is used to measure the flow-response time, it is very important that the speed of the time drive be accurately known.
CALIBRATION AND ACCURACY
The thermal-pulse flowmeter should be calibrated, perhaps by using a borehole-flowmeter calibration facility similar to that shown in figure 7. Direct calibration of the flowmeter avoids the problem of trying to determine the exact relation between the flow in the flow-sensor tube and the total flow in the borehole. The fluid velocity in the flow sensor usually will be somewhat less than in the borehole because of the interacting effect of probe size and geometry, borehole diameter, water viscosity, and so forth. The U.S. Geological Survey's flowmeter-calibration facility consists of four vertical clear plastic columns with inside diameters of 2, 3, 4, and 6 in.; and a reservoir, circulating pump, flow controls, and measuring instruments. The system can circulate and measure water volumes ranging from 0.1 to 8.0 gal/min to produce average water velocities (either up or down) ranging from a minimum of 0.06 ft/min in the 6-in.-diameter column, to a maximum of 50 ft/min in the 2-in.-diameter column.
For calibration, the thermal-pulse flowmeter with its centralizer is positioned in the center of the column, and a metered flow of water is circulated through the column at the desired rate and direction. The water needs to be free of any gas that could collect on the heater grid and thermistors. One way to ensure this is to fill the system reservoir with hot water and let it cool overnight. Another way is to cool the reservoir water with cold water through temperature-control coils in the reservoir. The water temperature needs to be adjusted to match the room air temperature near the flow column to avoid thermal convection currents in the water. Even a
13
4 DIAMETER OF COLUMN IN INCHES
-0.75 -0.50 -0.25 0 0.25 0.50
FLOWMETER RESPONSE, IN HERTZ
0.75
-1 -1.33 - 2 -4 cx=> 4 2
FLOWMETER RESPONSE, IN SECONDS
1.33
Figure 8. Calibration example of a thermal-pulse flowmeter in 2-, 3-, 4-, and 6-inch diameter columns at 25°Celsius.
10 20 30
TEMPERATURE, IN DEGREES CELSIUS
Figure 9. Relative zero-flow response in water as a function of temperature.
1°C difference in temperature may cause a calibration error that is measurable at very slow flow rates (Hess 1986). The system temperature and flow rate need to be adjusted and allowed to stabilize for at least 5 min before starting calibration measurements. Longer stabilization times may be needed for the slower velocities. To obtain repeatable measurements, allow at least five trigger to flow-response times between trigger pulses, or 10 min, whichever is the lesser, to permit the effects of the heat pulse to dissipate, and for the flow through the flow sensor to stabilize after each pulse. Thus, a flow measurement cycle may take from only a few seconds for flow velocities of 10 ft/min or greater, to 10 min or longer for velocities of 0.3 ft/min or less. The system has adequately stabilized when three or more consecutive measurements agree to within a few percent and no longer show a monotonic drift trend. The average of the last several measurements are used in determining the flow velocity.
A series of measurements should be made across the velocity range achievable by the system, including zero flow, in each diameter column. These measurements may be plotted and fitted with a best-fit curve to form a family of calibration curves such as those shown in figure 8; this family of curves was made for a thermal-pulse flowmeter in columns having diameters of 2, 3, 4, and 6 in. The vertical coordinate in figure 8 is the actual water volume flow in the column, positive for upflow and negative for downflow. The horizontal coordinate is the time (actually inverse time) for the corresponding pulse response of the flowmeter, right for positive-response pulses and left for negative-response pulses. The use of inverse time, s~x or hertz, permits the calibration curve to be a continuous, nearly straight line through the zero flow range. The temperature of the sheet of water heated by the thermal pulse is only a few tenths of a degree higher than the ambient water temperature but that is enough to give it a slight positive buoyancy. This buoyancy produces a slight upflow bias that causes the calibration curves to be slightly asymmetric at very slow velocities. A slight difference in the spacing between the heater grid and the upflow and the downflow sensors will cause the calibration curves to be asymmetric at higher flow velocities.
The uncertainty of the thermal-pulse flowmeter calibration by the U.S. Geological Survey's facility is estimated to be no more than 5 percent of the indicated flow plus 0.1 ft/min at room temperature (about 23°C). Water temperatures in boreholes usually are lower than 23°C, usually ranging from 10 to 20°C, but borehole temperatures may range from freezing to boiling (or greater in geothermal wells). The thermal-pulse flowmeter calibration is slightly temperature dependent because of the change in water density and viscosity with temperature (Hess 1986), so a small temperature-dependent correction factor may need to be applied to the calibration curve, especially at slower velocities. A typical temperature-dependent zero-flow response curve is shown in Figure 9. Notice that at 4°C a thermal-pulse-heated sheet of water has neutral buoyancy, and therefore has no net zero-flow bias; whereas at temperatures below 4°C a heated sheet of water has a slight negative buoyancy and the zero-flow bias is negative. This effect is seen in the low temperature end of the zero-flow response of the curve in figure 9.
15
FLO
W V
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ES
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ELS
IUS
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34
5 7
8 9-1
.0
-0.5
200
<
400
_i O
600
800
1,00
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o u.
230-
9
240-
0.03
-0.3
5
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35
-0.3
5
-0.5
0
-0.8
0
I -0
.95
{-0.
85
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80
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-_-U
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XP
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OW
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EE
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OW
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S T
HA
N
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OW
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R
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SO
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03
Figu
re 10
. Caliper, temperature,
an
d fl
ow ve
loci
ty
logs
of
URL-10,
modified from
Keys
(1984).
Figu
re 11
. Ac
oust
ic televiewer logs of
se
lect
ed de
pths
of URL-10,
modi
fied
fr
om K
eys
(1984).
The zero-flow response of the thermal-pulse flovmeter may be checked in a borehole by positioning the flowmeter at a depth where it is known that there is no flow; such as in the casing just below the water level that is known to be static, and where the temperature gradient is zero or the temperature decreases with depth.
EXAMPLE OF THE USE OF THE THERMAL-PULSE FLOVMETER
A logging trip to assist in the study of fracture hydrology in a granite pluton near Lac du Bonnet in Manitoba, Canada, afforded an opportunity to demonstrate the slow flow measuring capability of the U.S. Geological Survey's thermal-pulse flowmeter. The Canadian site is being developed by Atomic Energy of Canada, Limited, as the Underground Research Laboratory to conduct geotechnical research and to validate predictive models as part of Canada's Nuclear-Fuel, Water-Management program. An overview of the geology of the area is given in a 1983 report by Green and Mair. Flowmeter logs were used along with caliper, temperature, and acoustic-televiewer logs to determine which fractures actually were transmitting water during the then-existing conditions. The borehole described in this report was unpumped during the measurements, but pumping tests later were determined to have been conducted in nearby boreholes during part of the flow test, and the flow in the borehole apparently was affected by these pumping tests.
The thermal-pulse flowmeter was operated from the U.S. Geological Survey's borehole logging van through about 6,000 ft of conventional four-conductor logging cable (five-conductors when the cable armor is included). The same precautions were taken when making flow measurements at the borehole site as were taken during flowmeter calibration in the laboratory. Adequate time, usually about 5 min, was allowed after the flowmeter was positioned at the desired depth to permit any water turbulence caused by moving the flowmeter through the water to cease and for the natural flow to re-establish itself. Then five instrument-response-time periods or 10 min, whichever was the lesser, was allowed between measurements to permit the thermal pulse to move out of the sensor, or to dissipate. A minimum of three measurements were made at each depth, which required from just a few minutes for velocities of 2 ft/min or greater, to as much as 40 min for velocities of 0.2 ft/min or less. The flow was considered to have adequately stabilized when repeated measurements agreed to within a few percent.
The measurements of this example were made in a borehole that is 3 in. in diameter and 1,000-ft deep (URL-10), and which deviated more than 20° from the vertical. Thermal-pulse flowmeter calibration in a laboratory column oriented 20° from the vertical virtually was almost identical to those calibrations made in the vertical column. Furthermore, because a thermal pulse has almost neutrally buoyant at a water temperature of about 8°C in the borehole, it was concluded that the borehole deviation had practically no effect on the flowmeter response. See the discussion in the previous section regarding temperature related corrections to the calibration of the flowmeter. Caliper, temperature, and flow-velocity logs of this hole are shown in figure 10; acoustic televiewer logs of the fractures at several depth intervals of interest are shown in figure 11.
The caliper log in figure 10 is quite smooth except for a large-aperture fracture at a depth of 308 ft, and smaller-aperture irregularities at a depth
17
of 285 ft and between 935 to 948 ft. The shape of the temperature-log suggests a downward movement of water between 226 and 942 ft with a slight change in flow at a depth of 308 ft.
The flowmeter log dated 7/14/83 indicates little flow (less than 0.03 ft/min) above a depth of 223 ft. A downward flow of about -0.36 ft/min was evident below a depth of 231 ft, downward flow increased from -0.36 to -0.9 ft/min between depths of 295 and 315 ft, and increased further to -0.95 ft/min at a depth of 741 ft. This downward-flow velocity remained nearly constant to a depth of 896 ft. At a depth of 938 ft, the flow had decreased slightly from -0.95 to about -0.8 ft/min, and at depth of 945 ft, the flow was less than 0.01 ft/min.
The flowmeter log dated 8/3/83 (fig. 10), made about 2 weeks later, indicated the same flow pattern but the flow velocity was only about two-thirds of the flow velocity of the earlier log. Later it was learned that pumping tests were being conducted in a borehole about 1,000 ft away during the earlier flow measurements but not during the later measurements. The termination of the pumping tests apparently caused the change in flow rate. These later measurements indicated that water was entering the borehole in the depth interval between 223 and 312 ft, and that the depth interval between 307 and 311 ft was the major contributor (about 60 percent of the flow). Fractures in the depth interval between 738 and 745 ft contributed another 10 to 15 percent to the total flow. Most of this flow exited the borehole near the bottom, in the depth interval between 942 and 944 ft.
The flow volume, Q, in gallons per minute, may be determined from the relation:
Q = 0.0408 x V x D2 , (1)
where V equals flow velocity, in feet per minute, and D equals borehole diameter, in inches. The 0.0408 value is derived from the determination of the volume of 1 ft of borehole.
The acoustic televiewer logs in figure 11 are plotted on an expanded depth scale and show a group of fractures in the depth interval between 223 and 232 ft, section A; the widest fracture is at a depth of 228 ft. Because these fractures were not detected by the caliper log, they apparently have rather small apertures. However, the flowmeter and temperature logs show that some downward flow was originating in this depth interval. Log section B shows another group of fractures in the depth between 302 and 314 ft; the widest fracture is at a depth of 308 ft. The fracture at a depth of 308 ft has the widest aperture seen on the caliper log, and this fracture is a major water contributor. Log section C shows a small group of fractures at a depth of about 741 ft, where downward flow again increased slightly. Near the bottom of the borehole, log section D shows a large group of fractures in the depth interval between 932 and 955 ft, with a wide, dark fracture area in the depth interval between 935 and 938 ft. However, as already noted, the majority of the flow was exiting in the depth interval between 942 and 944 ft, probably through the small fracture indicated on log section D at a depth of 942.6 ft. The acoustic televiewer logs show many fractures scattered throughout the borehole, but only a few discrete fractures appear to have
18
been transmitting water during the hydraulic-head conditions that existed at the time of measurements.
The flowmeter logs in figure 10 have a resolution of about 0.03 ft/min. However, the actual uncertainty of the flow velocities may be as much as 0.1 ft/min as was discussed in a previous section. A more complete discussion of the fracture hydrology and the integration of flowmeter results with other geophysical data for this borehole is given in a report by Keys (1984), and a hydrogeological characterization of the Underground Research Laboratory site is given by Davison (1984).
SUMMARY
This report has described the theory of operation, construction, calibration, and use of a sensitive thermal-pulse flowmeter developed by the U.S. Geological Survey for measuring the movement of slow-velocity water in boreholes. The flowmeter, which uses the thermal-tag/trace-time principle, has a useful flow measuring range of from about 0.1 to more than 20 ft/min, and has a resolution of about 0.03 ft/min. It has no moving parts and distinguishes between upflow and downflow. The slight buoyancy effect in the thermal-pulse flowmeter caused by a change in density of thermal-pulse heated water usually is less than 0.2 ft/min and is accounted for during calibration.
The thermal-pulse flowmeter is more than an order of magnitude more sensitive than the traditional spinner-type flowmeter, and it is faster and more accurate than radioactive- or brine-solution tracer flow measuring techniques. The later techniques are characterized by relatively large errors caused by the differences in the densities between the borehole and the tracer fluids, or the existence and effect of convection currents in the borehole that usually are ignored or are inadequately accounted for.
Two sizes of flow sensors are described; the 1 5/8 in. diameter flow sensor is useful in boreholes with diameters of 2 to 4 in. The 2 1/2 in. diameter flow sensor is useful in boreholes with diameters equal to or larger than 3 in. The borehole configured thermal-pulse flowmeter does not replace the traditional spinner-style flowmeter, but rather complements it, greatly extending the lower range of accurate water velocity (and volume) measurements available to hydrogeologists and others studying ground-water movement.
19
REFERENCES CITED
Bird, J.R., and Dempsey, J.C., 1955, The use of radioactive tracer surveys in water-injection wells: Lexington, Kentucky Geological Survey Special Publication 8, 11 p.
Chapman, H.T., and Robinson, A.E., 1962, A thermal flowmeter for measuring velocity of flow in a well: U.S. Geological Survey Water-Supply Paper 1544-E, 12 p.
Davison, C.C., 1984, Hydrogeological characterization at the site of Canada's Underground Research Laboratory: An International Ground-water Symposium on Groundwater Resources Utilization and Contaminant Hydrology, Pinawa, Manitoba, 1984, Proceedings, v. II, p. 310-335.
Dudgeon, C.R., Green, M.J., and Smedmore, W.J., 1975, Heat-pulse flowmeter for boreholes: Medmenham, Marlow, Bucks, England, Water Research Centre Technical Report TR-4, 69 p.
Edwards, J.M., and Bolter, E.L., 1962, Applications of a subsurface solid-state isotope injector to nuclear-tracer survey methods: Journal of Petroleum Technology, v. 14, no. 2, p. 121-124.
Green, A.G. and Mair, J.A., 1983, Subhorizontal fractures in a granitic pluton Their detection and implications for radioactive waste disposal: Geophysics, v. 48, no. 11, p. 1428-1449.
Hess, A.E., 1982, A heat-pulse flowmeter for measuring low velocities in boreholes: U.S. Geological Survey Open-File Report 82-699, 44 p.
1986, Identifying hydraulically conductive fractures with a slow-velocity borehole flowmeter: Canadian Geotechnical Journal, v. 23, no. 1, p. 69-78.
Kerfoot, W.B., 1982, Comparison of 2-D and 3-D ground-water flowmeter probes in fully-penetrating monitoring wells: National Water Well Association Symposium on Aquifer Restoration and Ground Water Monitoring, 2d, Worthington, Ohio, 1982, Proceedings, p. 264-269.
Keys, W.S., 1984, A synthesis of borehole geophysics data at the Underground Research Laboratory, Manitoba, Canada: U.S. Department of Energy, BMI/OCRD-15, 43 p.
1987, Borehole geophysics applied to ground-water investigations: U.S. Geological Survey Open-File Report 87-539, 305 p.
Keys, W.S., and MacCary, L.M., 1971, Application of borehole geophysics to water-resources investigations: U.S. Geological Survey Techniques of Water-Resources Investigations, Book 2, Chapter El, 126 p.
Miller, T., Jr., and Small, H. 1982, Thermal pulse time-of-flight liquid flowmeter: Analytical Chemistry, v. 54, no. 6, p. 907-910.
20
Morrow, T.B., and Kline, S.J., 1971, The evaluation and use of hot-wire and hot-film anemometers in liquids: Palo Alto, Calif., Stanford University, Department of Mechanical Engineering, Thermosciences Division Report MD-25, 187 p.
Patten, E.R., and Bennett, G.D., 1962, Methods of flow measurement in well bores: U.S. Geological Survey Water-supply Paper 1544-C, 28 p.
Skibitzke, H.E., 1955, Electronic flowmeter: U.S. Patent No. 2,728,225.
Tselentis, G.A., 1984, An investigation of the principles of operation of the heat-pulse flowmeter: Journal of Hydrology, v. 69, p. 335-349.
21
GLOSSARY
The following terms, abbreviations, and definitions are used in this report:
ac a alternating current ADJ a ad j us t AMP a amplifier ATV = acoustic televiewerBNC a the International Electronics Commission designation for a
specific type of electronic coaxial connector
C = capacitor, an electronic component (C) a a commercially available part CHG - chargeCHG/TRIG - a 2-position switch so labeled CYL a cylinder, or cylindrical
D. = diameter, when used with or as a dimensionD = diode, when used as an electronic componentdc a direct currentDIA a diameterDISC SB discriminator control
DPM a digital panel meterDWG = drawingea = eachFLOW ADJ = a screwdriver-adjustable flow-zero controlF a farad, unit of capacitance, an electrical quantity
ft a footft/min a foot per minuteheat-pulse « thermal-pulseHHz
^ V V W f ̂M ̂ » * * * V* W ̂
se « thermal-pulsehenry, unit of inductance, an electrical quantityhertz (cycles per second)
HTR = heaterHV = heater voltageHV ADJ « a screwdriver-adjustable heater-voltage controlHV/FLOW « a 2-position switch so labeledHV-RDY = heater-voltage ready light
HV-TEST « heater-voltage test connector1C « integrated circuit, an electronic componentID = inside diameterin « inchin/min = inch per minute
L - length, when used as a dimensionL = inductor, when used as an electronic componentLCD a liquid crystal displayLED « light emitting diode displayMAT'L a material
22
GLOSSARY continued
min = minute(time)NEF = national extra fine (thread)NF = national fine (thread)NIM = Nuclear Instrumentation Module, an instrument module which
physically slides into, and electrically receives it's powerfrom a NIMs-BIN.
NIMs-BIN = a metal case which physically supports one or more NuclearInstrument Modules and provides them with electrical power.
NPT = national pipe thread0-ring = a "rubber" seal shaped like the letter "0" OFF = off position of switch
ON = on position of switchON/OFF = a 2-positon switch so labeledOUT = outputPCB = printed circuit boardPN = part numberPS = power supply
psi = pounds per square inchQ = flow volume, gallon per minute, when used in a flow formula.Q = transistor, when used as an electronic componentR = resistor, an electronic componentREG/TEST = recorder-test connector
REF = reference, a dimension given for convenience, but not to be usedfor determining parts tolerance.
REG = regulator s = second(time) SCR = silicon controlled rectifier, an electronic component
spinner = a spinning type flowmeterSIG/TEST = signal-test connectorSS = stainless steelSTD = standardSurvey = United States Geological Survey
Sw = switchT = transformer, an electronic componentTC = temperature coefficientTh = thermistor, a resistor that has a large negative temperature
coefficient thermal-pulse = heat-pulse
THD = threadTHD/IN = thread per inchTPFM = thermal-pulse flowmeterTRIAC = a dual silicon controlled rectifier for ac circuitsTRIG - trigger
23
GLOSSARY continued
TRIG ADJ = a screwdriver-adjustable trigger-pulse amplitude controlU = integrated circuit, an electronic componentUN = unified national (thread)UNF - unified national fine (thread)USGS = United States Geological Survey
V = voltage, when used as an electrical quantityV m velocity, when used as a mechanical quantityw = watt of power, when used as an electrical quantityx = times .(miltiply)W = wide, when used in mechanical drawings
Z = zener diode, an electronic component
Other abbreviations used
52 = ohm, a unit of resistance, an electrical quantity/ = per (divided by)(_ = angle0 = degree, angle, when used in mechanical drawings" = inch(es), when used with dimensions
Dimensional prefixes used
M-k-m-u-n-P-
= mega == kilo == milli== micro== nano == pico =
xlO*v1 O / "i Am\j n \ JL . c .xlO ,xl°~QxlO~^0xlO"
18 kHz = 18 kilohertz = 18 x 103 hertz)
24
Table 1. Mechanical parts list for the thermal-pulse flowmeter probe.
Part Figure number number
12345
67899A
10111212A13
13A1414A1515A
161718ISA19
2021222324,25
26272828A2930
3132333435-39
F-12F-13F-14F-15F-16
F-17F-38F-37F-18F-20
no dwgF-21F-22F-23F-24
F-25no dwgno dwgF-26F-27
no dwgF-28F-19F-20no dwg
F-29F-30F-31F-31no dwg
F-32F-17F-33F-34no dwgF-35
F-35F-36F-39,40no dwgno dwg
Description
Probe connector subElectronics case (tube)Top centralizer slide (1 5/8"D.)Top sensor bulkheadBow spring
Split ring slide stop (spring)Hi-pres. connector and cable (C)Thermistor (C)Top fin (1 5/8"D)Top fin (2 1/2"D)
Set screws, (C)Thermistor postTop flow tube (1 5/8"D)Top flow tube (2 1/2"D)Heater frame (1 5/8"D)
Heater frame (2 1/2"D)0-ring, 2-025 (for 1 5/8"D) (C)0-ring, 2-033 (for 2 1/5"D) (C)Bottom flow tube (1 5/8"D)Bottom flow tube (2 1/2"D)
Cone BushingBottom sensor bulkheadBottom fin (1 5/8"D)Bottom fin (2 1/2"D)0-ring, 2-024 (C)
Bottom connector coverBottom centralizer slideBottom slide mandrel(l/4" nipple)(C)Cap, 1/4" (C), modified(no part)
Probe connector carrierConnector clamp screwHeater assembly jig (1 5/8")Heater assembly jig (2 1/2")(no part)Bulkhead, electronic chassis
Bulkhead, bottom connectorPrinted circuit board support blockRail for electronic chassisInsulator, standoff (C)(no part)
Number Material per set
stainless steel*stainless steelbrassstainless steelstainless steel
stainless steel
stainless steelstainless steel
stainless steelstainless steelstainless steelstainless steelNylon or Delron
Nylon or DelronVitonVitonstainless steelstainless steel
Nylon or Delronstainless steelstainless steelstainless steelViton
stainless steelstainless steelstainless steelss or brass
brassbrassbrass or steelbrass or steel
brass
brassbrasssteel
11214
13244
22111
1
11
11444
1111
1
11
3
1123
25
Table 1. Mechanical parts list for the thermal-pulse flovmeter probe, continued
Partnumber
4041424344
454647
NOTES:
Figurenumber Description
F-37 Connector, 4-pin, female (C)no dwg Connector, 6-pin, male (C)F-41 Connector, 6-pin, female (C), modifiedno dwg (no part)F-38 Hi-pressure feedthru (C)
F-38 Hi-pressure connector with cable (C)F-38 Hi-pressure connector (C)F-37 Insulating boot, 4-pin (C)
(1) Material: stainless steel to be high strength
Numberper set
111
4
311
non-corroding.(2) (C) indicates that the part is commercially available, for
special items see table 3.(3) Break (round) all edges unless otherwise stated.(4) All dimensions are in inches and all tolerances
inch unless otherwise stated.are +/- 0.005
COMMERCIAL AVAILABLE HARDWARE FOR PROBE:
Screws & nuts used with (part #)
4-40 X4-40 X4-404-40 X 5/8" panhead3-48 X 7/8"
4-40 nuts
Stainless steel
Material, (steel except
as noted) Rail (30)Bow spring slide (3),(21)Probe PCS mounting blocks (32)Probe PCS mounting blocks (32)
panhead (or fillister head, turned to 0.165"D.)6-pin connector (42)Probe PCB mounting blocks
1/4" flathead 1/4" panhead
X 3/8" panhead
Number per set
204
1212
212
0-RINGS: (Part numbers are for Parker Seals, or equivalent; material, Viton)
Part number
191414A
Parker size
2-0062-0112-0132-0242-0252-0332-115
Inside diameter X width
1/8 X 1/165/16 X 1/167/16 X 1/161 1/8 X 1/161 3/16 X 1/162 X 1/1611/16 X 3/32
Part used with
Hi-pres. feed-thrusThermistor postGOI 4-pin connectorElectronics caseHeater (1 5/8"D)Heater (2 1/2"D)GOI connector carrier
Part No.
(44)(11)(40)(2)(13)
(13A)(26)
Number per set
3224111
26
Table 2. Electronic-parts list for thermal-pulse flowmeter probe
Partnumber Description
CAPACITORS (All are non-polarized except as noted):
Cl 78uF/50v electrolyticC2 1.5F/15v electrolyticC3 6uF/15v electrolyticC4,5 1.5F/15v electrolyticC6 InF
C7 lOOpFC8 InFC9 33uF/15v electrolyticCIO 5nF*Cll-14 1.5uF/15v electrolytic
C15 lOnFC16 33uF/15v electrolyticC17,18 1.5F/15v electrolyticC19 lOOnFC20 2xlOOuF/450v electrolytic
DIODES (as shown or equivalent):
Dl 1N2989B, 30V/lOv, zenerD2 1N4001D3-10 1N914Dll 1N4005
TRANSISTORS (as shown or equivalent):
Ql CA40361Q2 2N3096Q3 2N4443Q4 2N3904
27
Table 2. Electronic-parts list for thermal-pulse flowmeter probe, continued
Partnumber Description
RESISTORS (all are 1/4W except as noted):
Rl R2 R3 R4 R5
R6 R7 R8 R9,10
R13,14R15-17R18R19R20,21
R22 R23 R24 R25 R26
R27 R28 R29 Heater
TH1&TH2
100 OHM, l/2w100k10 OHM2k28k
10k2M680k100k10k
2k2 10k
*1M*10k 5kl
10k470k4k7470knone
2k210 OHM, l/2w10k, l/2w5 to 50 OHM, hand made using insulated resistance wire,0.020-inch diameter or smaller.50k, thermistor, temperature sensors, (commercial part listed intable 3).
NOTES:* Stable, low temperature coefficient components.
Ul U2 U3 U4
INTEGRATED CIRCUITS:
7812, 12V regulator74C14, hex inverterCA4046, voltage controlled oscillatorLF343, dual operational amplifier
28
Table 3. Electronic-parts list for the thermal-pulse flowmeter surface module.
Partnumber Description
CAPACITORS: (all are non-polarized except as noted, i.e. 60uF/400v, electrolytic)
Cl 60uF/400v, electrolyticC2 O.luFAOOvC3-5 78uF/35v, electrolyticC6 47uF/35v, electrolyticC8 2nF
C9 *lnFC10-12 1.5uF/15v, electrolyticC13 O.luFC14 3uF/+15v, electrolytic
DIODES (all are 1N914 or equivalent except as noted)
Dl-4 1N4004 or 400v diode bridgeD5 1N5230, 4.5v zenerDll LED, redD14 1N5232, 5.5v zenerD20 1N279 (Germanium)
RESISTORS (all are +/-5%, l/4w except as noted)
Rl IkR2 Ik trimpotR3 100kR4 Ik, IwR5 390 ohm
R6 Ik, IwR7,8 22MR9 300kRIO 240kR12 3k3
R13-15 IkR16 100kR17 510 ohm, l/2wR18 18kR19 100k
29
Table 3. Parts list for the thermal-pulse flowmeter surface panel, continued
Partnumber Description
RESISTORS (all are +/-5%, l/4w except as noted)
R20 *200k, 1%R21 *5k trimpotR22 *20k, 1%R23 IkR24 9kl
R25 5k trimpotR26 noneR27 22kR28 220 ohmR29 2k2
R30,31 51kR32 2k7R33 *51kR34 20kR35 10k
R36R37R38R39R40R41
R42R43R44R45
2k210k trimpot10k10k trimpot9klIkO
5kl15k2k220 ohm
NOTES: * = stable, low temperature components
Partnumber Description
51 Switch, double-pole, double-throw, spring return52 Switch, 4-pole, single-throw53 Switch, single-pole, double-throw
30
Table 3. Parts list for the thermal-pulse flovmeter surface panel, continued
Partnumber Description
Integrated circuits, (as indicated or equivalent)
Ul CA4093, Quad S.T. NAND, CMOSU2,U3 LF353, Dual operational amplifier, CMOSU4 CA4528 (or CA40989) dual 1-shot, CMOSU5 Vactec VACTROL, 76 32 VTL 5C3, photo relayU6 MOC-3010, optically coupled triacU7 7805, 5v regulator
Miscellaneous: (Quantity: 1 each or as specified)
BNC-F Front panel coaxial connectors, BNC-F 3 eaD15-F Rear connector, D15-F (15-PIN)NIM NIMs panel, 2-videDPM Panel meter, 3-digit, +/-lv, Electronics, Inc., model MDPM (or equiv.)Tl Power transformer, 120v input, 250v ouput, lOv
31
Table 4. Sources of commercial parts used in thermal-pulse flowmeter.
Most hardvard is available from hardware supply houses, and most electrical/electronic parts are available from electrical/electronic supply houses. Some special parts are listed below.
Part number
7 44 46
8
40
47
41 42
Figure number
F-38 F-38 F-38
F-37
F-37
F-37
no dwg F-41
Mfgs P/N
16-B-1042 16-A-131 16-B-430
GA45P2S(special)
04-9715-30
06-9705-26
BURNDY-BT06E10-6PN BURNDY-BTOOEC10-6SN
Manufacturer and address
Kemlon Pr oduc t s , P . 0 Houston, TX 77021 Phone (717)747-5020
Fenwall Electronics, Blvd., Millford, MA Phone (617)478-6000
.Box 14666,
450 Fortune 01757
Gearhart Industries, Fort Worth, TX, or Brantner & Assn. Inc. , 3501 Hancock St., San Diego, CA 92110
or MS3116F10-6P, Arrow Electronics or MS3110F10-6S " "
DPM
NIM
F-5
F-5
MDPM-111
2-wide NIMs module
Electronics Incorporated, 1520 N. Main St., Mishawaka, IN 46545, Phone (219)256-5001
Tennelec, 601 Oak Ridge Turnpike,P.O. Box 2560, Oak Ridge, TN37831-2560Phone 615)483-8405
32
0.06:
0.400
PART NUMBER 1
8THD PER INCH 1.115Dx 0.032 DEEP STUD ACME
0.06
0.100 > 0.180 0.280 0.360
0.055-0.056 DEEP 0.15 > x 0.080 WIDE
0.750-
0.4203.100
PROBE CONNECTOR SUBMATERIAL: NON-CORROSIVE STAINLESS STEELSCALE: 1 INCH = 1 INCH
Figure 12. PN-1, probe connector sub
33
1 1/4
-16 T
HD
1
.18
2-1
.19
6 D
00
fTT
TT
T/T
T???////////////,
PA
RT
NU
MB
ER
2
ELE
CT
RO
NIC
S C
AS
EM
AT
ER
IAL
: N
ON
-CO
RR
OS
IVE
ST
AIN
LE
SS
ST
EE
LS
CA
LE:
1 IN
CH
=
1 IN
CH F
igure
13
. P
N-2
, ele
ctr
on
ics
case
.
4-0
.27 W
IDE
S
LOT
S A
T 9
0°
OO
Ln
DR
ILL
AN
D T
AP
(R
AD
IAL
LY
) 2-
HO
LES
FO
R 4
-40
(U
SE
S
TA
INL
ES
S S
TE
EL
PA
N H
EA
D S
CR
EW
S
TO
AN
CH
OR
WIR
E )
WIR
E G
RO
OV
E -
0
.05
0W
IDE
x
0.0
50
DE
EP
/ia
BE
VE
L
PA
RT
NU
MB
ER
3
TO
P C
EN
TR
ALI
ZE
R S
LID
E
MA
TE
RIA
L:
BR
ON
ZE
SC
ALE
1
INC
H-1
IN
CH
Fig
ure
14
. P
N-3
, to
p centr
ali
zer,
sl
ide.
4 FI
N S
LO
TS
0.04
0 W
IDE
X 0
.030
DE
EP
90°
AP
AR
T
3.90
RO
UN
D T
O M
AK
E A
SM
OO
TH
S
TR
EA
MLIN
ED
T
RA
NS
ITIO
N F
RO
M
CO
NE
TO
CY
LIN
DE
R,
AP
PR
OX
IMA
TE
LY
A 3
-IN
CH
R
AD
IUS
3 F
EE
D-T
HR
OU
GH
H
OLE
S 9
0°
AP
AR
T
0-R
ING
GR
OO
VE
5
/ I 6
-24
NE
F
3 F
EE
D-T
HR
OU
GH
H
OLE
S 9
0°
AP
AR
T
0.2
50
-0.2
51
D
. V
3 H
OLE
S O
.I5
0 D
EE
P (
SE
E
PN
44)
C-R
ING
GR
OO
VE
0
.10
5 W
IDE
X 0
.050 D
EE
P,
AT
AP
PR
OX
IMA
TE
LY
1.
275
D
2 O
-RIN
G
GR
OO
VE
S (
N2-0
24)
1.1
38D
. 0.
090
WID
E
DR
ILL
AN
D T
AP
2 E
QU
ALLY
SP
AC
ED
,3
-48 N
FX
3/1
6
DE
EP
HO
LES
ON
0
.77
0 D
CIR
CLE
PA
RT
NU
MB
ER
4
TO
P S
EN
SO
R B
ULK
HE
AD
M
AT
ER
IAL
: S
TA
INL
ES
S S
TE
EL
S
CA
LE
: I
INC
H =
I
INC
H
Fig
ure
15
. P
N-4
, to
p
sen
sor
bulk
head
,
ALT
ER
NA
TE
: F
OR
M
V* -
INC
H
WID
E
EN
D E
YE
SIN
Ve-
INC
H
DIA
ME
TE
R S
PR
ING
WIR
E
k 11
1(R
EM
OV
E T
EM
PE
R F
RO
M
EN
DS
TO
F
OR
M E
YE
. D
O N
OT
RE
TE
MP
ER
.)
1I
I
/16
(O
R T
O S
UIT
AP
PL
ICA
TIO
N)
U)
*A
EY
E 0
.05+
I.D
. (B
OT
H
EN
DS
)
^ <
t.._ 1
1H
R IN
MA
TE
RIA
L L
EN
GT
H A
PP
RO
XIM
AT
EL
Y
19 I
NC
HE
S
(OR
TO
SU
IT A
PP
LIC
AT
ION
)
PA
RT
NU
MB
ER
5
BO
W S
PR
ING
(4
PER
SE
T)
MA
TE
RIA
L:1/
4 IN
CH
WID
E x
V
16 T
HIC
K
(OR
TO
SU
IT)
FLA
T S
TA
INLE
SS
SP
RIN
G S
TEE
L
SC
ALE
: 1
INC
H =
1 I
NC
H
FO
RM
S
PR
ING
IN
TO
A 5
-IN
CH
B
OW
AN
D T
EM
PE
R
Fig
ure
16
. P
N-5
, bo
w sp
rin
g.
U)
00
0.20
SIN
GLE
SLO
T
0.05
0 W
IDE
X
0.0
75
DE
EP
PA
RT
NU
MB
ER
6
SP
LIT
-RIN
G S
LID
E-S
TO
P
MA
TE
RIA
L:
ST
AIN
LES
S S
TEE
L or
BR
ON
ZE S
PR
ING
WIR
E
SC
ALE
: 1
INC
H=1
IN
CH
/8-1
8T
HD
PA
RT
NU
MB
ER
27
CO
NN
EC
TO
R C
LAM
P S
CR
EW
M
AT
ER
IAL:
B
RA
SS
S
CA
LE:
I IN
CH
=
I IN
CH
Figu
re 17
. PN-6,
spli
t ring slide
stop
; PN-27, conn
ecto
r clamp
screw.
14°
14°
UJ
VO
TA
PE
R
TWO
E
XP
OS
ED
ED
GE
S
AP
PR
OX
IMA
TE
LY
14°
EN
D V
IEW
0.5
57
PA
RT
NU
MB
ER
9T
OP
FIN
|
5/8
MA
TE
RIA
L:
0.05
-IN
CH
TH
ICK
ST
AIN
LE
SS
ST
EE
L
SC
ALE
: 1
INC
H =
1/2
IN
CH
Fig
ure
18
. P
N-9
, to
p fi
n,
1 5
/8.
14°
14°
TA
PE
R T
WO
ED
GE
S
AP
PR
OX
IMA
TE
LY
14°
0.4
00
EN
D V
IEW
PA
RT
NU
MB
ER
18
BO
TT
OM
FIN
1
5/8
MA
TE
RIA
L:
0.05
-IN
CH
TH
ICK
ST
AIN
LES
S S
TEE
LS
CA
LE:
1 IN
CH
= 1
/2 I
NC
H
Figu
re 19
. PN
-18,
bottom fin, 1
5/8.
14° 14°
TAPER TWO EDGES V"1^ APPROXIMATELY 14° \ /
0.31
PART NUMBER 9ATOP FIN 2 I/2MATERIAL: 0.05-INCH THICK STAINLESS STEELSCALE: 1 INCH = 1 INCH
V
END VIEW
TAPER TWO EXPOSED EDGES APPROXIMATELY 14°14° 14°
2.50 >
0.37
49.2°END VIEW
PART NUMBER 18ABOTTOM FIN 2 I /2MATERIAL: 0.05-INCH THICK STAINLESS STEELSCALE: 1 INCH = 1 INCH
Figure 20. PN-9A, top fin, 2 1/2; PN-18A, bottom fin, 2 1/2.
41
H- OQ
n fl>to
3H- W rt On
13o(A
-0.311 -^- 0.312 D
n ** x1? > x ^̂pm o 3) w
0.155 -0.157 D
\ 0.25 HEX I
4 FIN SLOTS 90° APART 0.052 WIDE 0.030 DEEP
DETAIL 2X
0.03
3 SLOTS, .^-"^0.100 WIDE0.125 DEEP90°
t
2.4
' 1
APART.20°
\
0.70REFERENCE
i
70
t0.640--0.642 j|
1 0.3 r w <\ , T ,
k _
0.060
_^L_
P
^_
A
|\
^y,
I/yx
1 625Q *l
r i.125D. >|
=
^L.____ 1.37(
1
IkIfc1/%11ii\yy
ss^^^~^^ "
)- ^
<y
^>^ /
SEE DETAIL
/ROUND EDGE ^ 0.015 RADIUS
ROUND APPRC3.4-INCH RADI
NOTE: MAKE TRANCYLIh
STRB
----- 1 7/16-20THDt 1 1OQ / 4 1OCX I i -aoo/ i .OJa
TRANSITION FROM CONE TO CYLINDER SMOOTH AND
1.378D.
PART NUMBER 12 SECTION A'A'TOP FLOW TUBE I 5/8MATERIAL: NON-CORRODING STAINLESS STEELSCALE: 1 INCH = 1 INCH
Figure 22. PN-12, top flow tube, 1 5/8.
43
-P-
-P-
NO
TE:
RO
UN
D T
O M
AK
E T
RA
NS
ITIO
N
FRO
M C
YLI
ND
ER
TO
CO
NE
S
MO
OT
H A
ND
ST
RE
AM
LIN
ED
(A
BO
UT
A 3
-IN
CH
RA
DIU
S)
0.64
1 ±
0.0
01
0.3
60
3 W
IRE
S
LOT
S0.
100
WID
E x
0.1
25
DE
EP
90
° A
PA
RT
2 5
/16
-16
UN
S -
2B
TH
D
PA
RT
NU
MB
ER
12A
TOP
FLO
W T
UB
E
2 M
AT
ER
IAL:
S
TA
INLE
SS
STE
EL
SC
ALE
: 1
INC
H =
1 I
NC
H
'//
4 FI
N
SLO
TS
0.05
2 W
IDE
x 0
.03
DE
EP
90°
AP
AR
T
Fig
ure
23
. PN
-12A
, to
p
flow
tu
be,
2
1/2
.
0.10
6 ->
44
0.02
8 D
. H
OLE
S D
RIL
LE
D^"
" U
SIN
G T
HE
HE
AT
ER
A
SS
EM
BLY
JIG
, P
AR
T
28
« *
> V
ft --
Y/d
L6
6
0.3
40 ±
0.0
01
0.1
03
-0.1
05
<- 0
.106 (
RE
FEF J
A
J
do
C
CN
O
"Z
-+1
|
1 L_
,
EN
CE
)
t 0 o
i
o
? ?,-
1 CO r~
2
1 1
PA
RT
NU
MB
ER
13
1 5/
s- I
NC
H
HE
ATE
R F
RA
ME
M
AT
ER
IAL:
N
YLO
N (
OR
DE
LRY
N)
SC
ALE
: 1
INC
H =
1 IN
CH
Fig
ure
24
. P
N-1
3,
heate
r fr
ame,
1
5/8
.
0.1
06 ±
0.0
01
»
0.17
0
0.0
28
D.
HO
LES
(4
4),
HO
LES
DR
ILLE
D W
HIL
E
HE
AT
ER
F
RA
ME
IS
ON
AS
SE
MB
LY
JIG
, E
ND
A,
PA
RT
2
8A
ON
i T 0.10
<
0.1
06
±
0.0
01
RO
UN
D A
LL
CO
RN
ER
S
3 H
OLE
S
EA
CH
S
IDE
0.0
28
D.
HO
LES
(4
4 T
OT
AL
)
t\
!-i :
ir
/
.1
19 H
OLE
S 0
.028
D.
n S
PA
CE
D A
T 0
.10
' E
AC
H
SID
E
1 k
0.3
40
± 0
.001
PA
RT
NU
MB
ER
13A
21/
2-I
NC
H
HE
ATE
R F
RA
ME
M
AT
ER
IAL:
N
YLO
N (
OR
DE
LRY
N)
SC
ALE
: 1
INC
H=
1 I
NC
H
Fig
ure
25
. PN
-13A
, heate
r fr
ame,
2
1/5
.
* 1.240-1.242 D. » 0.050 -
0.052 ~T
1
1.8
U:0.294-
0.296
25
T 0.70 v/REF . '//
i rSEE DETAIL '"^/
//z_20°
r
!\^
'
**
\1
SECTION A-A' I
U 1.125D. »4
< -'1.625 D. >
1 7/T6 -20THD
(1.436/1.4280)
^.ROUND,APPROXIMATELY '3.4-INCH RADIUS
SEE NOTE
^ ROUND EDGE0.015 RADIUS
2 SLOTS,0.100 WIDE
_____ 0.125 DEEP - -~~~ 90° APART
NOTE: MAKE THE INSIDE SURFACE TRANSITION FROM CONE TO CYLINDER SMOOTH AND STREAMLINED
A'
PART NUMBER 15BOTTOM FLOW TUBE I 5/8MATERIAL: NON-CORRODING STAINLESS STEELSCALE: 1 INCH=1 INCH
Figure 26. PN-15, bottom flow tube, 1 5/8.
47
4 FI
N S
LOT
S0.
052
WID
E x
0.0
30 D
EE
P
90
° A
PA
RT
\
00
2 W
IRE
SLO
TS
0.10
0 W
IDE
x 0
.125 D
EE
P9
0°
AP
AR
T PA
RT
NU
MB
ER
15
AB
OT
TO
M F
LOW
TU
BE
2
I /2
M
AT
ER
IAL:
S
TA
INLE
SS
STE
EL
SC
ALE
: 1
INC
H =
1
INC
H
RO
UN
D E
DG
E
0.0
15 R
AD
IUS
SE
E D
ET
AIL
( 0
.70
*
RE
FE
RE
NC
E
1.82
5
SE
E N
OT
E
0.2
9510.0
01
< 0
.051
± 0
.001
Q
Q
Q
2 5
/16
- 16
UN
S -
2B
TH
D
NO
TE:
RO
UN
D T
O M
AK
E T
RA
NS
ITIO
N F
RO
M C
YLI
ND
ER
TO
CO
NE
S
MO
OT
H A
ND
ST
RE
AM
LIN
ED
(A
BO
UT
A 3
-IN
CH
RA
DIU
S)
0.03
Figu
re 27
. PN-15A,
bottom fl
ow tu
be,
2 1/2.
10 -
32
NF
5/8
- 24
NE
F
RO
UN
D T
O M
AK
E
TR
AN
SIT
ION
FR
OM
C
ON
E T
O C
YLIN
DE
R
SM
OO
TH
AN
D
ST
RE
AM
LIN
ED
(A
BO
UT
A 3
-IN
CH
R
AD
IUS
)
4 F
IN S
LO
TS
0.0
52 W
IDE
X
0.03
DE
EP
9
0°
AP
AR
T
0-R
ING
GR
OO
VE
(F
OR
N-2
-01
1 0
-RIN
G)
\ HO
LE B
RE
AK
T
HR
OU
GH
H
ER
E I
S
OK
AY
0.1
13 D
.or#
33
DR
ILL
A
PP
RO
XIM
AT
EL
Y 4
°i
SA
ME
FO
R 2
HO
LES
9
0°
AP
AR
T
PA
RT
NU
MB
ER
17
BO
TT
OM
SE
NS
OR
BU
LKH
EA
D
MA
TE
RIA
L:
ST
AIN
LES
S S
TEE
L S
CA
LE:
1 IN
CH
= 0
.5 I
NC
H
A'
SE
CT
ION
A-A
'
Figu
re 28
. PN
-17,
bo
ttom
sensor
bulkhead.
<0.4
0>
7
zz//
/
Ui
o
3.30
2.90
V4-
18 N
PT
PA
RT
NU
MB
ER
20
BO
TT
OM
CO
VE
RM
AT
ER
IAL:
ST
AIN
LES
S S
TEE
LS
CA
LE:
1 IN
CH
= 1
INC
H
VsD
IA.
HO
LE A
IR
BLE
ED
« o
o
5/a-24 NEF
Figu
re 29
. PN-20, bottom c
over.
WIR
E G
RO
OV
E -
0.0
50
WID
E
x 0.0
60
DE
EP
4-0
.25 W
IDE
S
LO
TS
AT
90
°
PA
RT
NU
MB
ER
21
BO
TT
OM
CE
NT
RA
LIZ
ER
SLI
DE
M
AT
ER
IAL:
B
RO
NZE
S
CA
LE:
1 IN
CH
=1
IN
CH
DR
ILL A
ND
TA
P (
RA
DIA
LL
Y)
2-H
OLE
S F
OR
4-4
0S
TA
INL
ES
S S
TE
EL
PA
N H
EA
D S
CR
EW
ST
O A
NC
HO
R W
IRE
Figu
re 30
. PN
-21,
bottom c
entralizer sl
ide
d' o
m
o1
k 1i
111 \ B(1 4
- 18
D
TH
E
NP
T
EN
DS
DR
ILL
'/4
D.
DR
AIN
H
OLE
N>
PA
RT
NU
MB
ER
22
BO
TT
OM
-SLI
DE
MA
ND
RE
L ,
. M
AT
ER
IAL:
B
RA
SS
OR
ST
AIN
LES
S S
TEE
L P
IPE
NIP
PLE
(C
) S
CA
LE:
1 IN
CH
= 1
INC
H
CO
MM
ER
CIA
LLY
AV
AIL
AB
LEP
AR
T N
UM
BE
R 2
31/
4-I
NC
H C
AP
1/4-
18N
PT
MA
TE
RIA
L:
BR
AS
S O
R S
TA
INLE
SS
STE
EL
SC
ALE
: 1
INC
H =
1
INC
HC
OM
ME
RC
IALL
Y A
VA
ILA
BLE
Fig
ure
31
. P
N-2
2,
bott
om sl
ide
man
drel
(1
/4
in pip
e nip
ple
) (C
);
PN
-23,
1/4
in
p
ipe
cap
(C).
Ui
U)
ON
E S
LO
T
DR
ILL
AN
D T
AP
FO
R
4-40
(4
EA
CH
) A0
-RIN
G G
RO
OV
E
(FO
R N
2-1
15 0
-RIN
G)
3^¥1
p ?
3.04
0
150
><
-H0.6
025
<±
0.0
025>
1.00
> fc
-
-0.06
PA
RT
NU
MB
ER
26
PROBE CONNECTOR CARRI
ER
MATERIAL:
BRASS
SCALE:
1 IN
CH = 1
IN
CH
Figu
re 32
. PN
-26,
probe
conn
ecto
r ca
rrie
r,
19 H
OLE
S 0
.031
D
.EA
CH
S
IDE
0.
050
SP
AC
ING
V3z
B
EV
EL
AT
45°
2 E
DG
ES
PA
RT
NU
MB
ER
28
AS
SE
MB
LY J
IGFO
R 1
5/8
- IN
CH
DIA
ME
TE
R H
EA
T G
RID
M
AT
ER
IAL:
B
RA
SS
OR
STE
EL
SC
ALE
: 1
INC
H =
1 IN
CH
3 H
OLE
S 0
.031
D
.0.
100
SP
AC
ING
E
AC
H
SID
E<4
4 H
OLE
S 0
.031
D
.TO
TA
L)
Figu
re 33
. PN
-28,
heater as
semb
ly jig,
1 5/8.
l<
0.1
70
±0.0
01
3 H
OLE
S 0
.031
D
EA
CH
S
IDE
W
K0.1
0
0.20
>\
PA
RT
NU
MB
ER
28A
AS
SE
MB
LY
JIG
FOR
2'/2
-IN
CH
DIA
ME
TE
R H
EA
T G
RID
MA
TER
IAL:
B
RA
SS
SC
ALE
: 1
INC
H-1
IN
CH
Fig
ure
34
. PN
-28A
, heate
r as
sem
bly
ji
g,
2 1/5
,
19 H
OLE
S E
AC
H S
IDE
0.
031
D.
(44
HO
LES
TO
TA
L
SP
AC
ED
AT
0.1
0
EA
CH
S
IDE
V 3 2 BEVEL AT 45°
DRILL AND TAP FOR 4-40 (2 EACH)
0.188
PART NUMBER 30BULKHEAD MATERIAL: BRASS SCALE: 1 INCH= 0.5 INCH
DRILL AND TAP FOR '/2-20 THD UNEF CENTER HOLE
PART NUMBER 31BULKHEAD MATERIAL: BRASS SCALE: 1 INCH = 0.5 INCH
1/32 BEVEL 45°
DRILL AND TAP FOR 4-40 (2 EACH)
Figure 35. PN-30, bulkhead; PN-31, bulkhead.
56
1 1 M i
'n
i-C
i
i
A
1 \
I ]I 0 in
M
d
in
Ul
0.12
0 D.
31 DRILL
PA
RT
NU
MB
ER
32
PR
INT
ED
CIR
CU
IT B
OA
RD
MO
UN
TIN
G B
LOC
K
MA
TE
RIA
L: 1/
4-IN
CH
SQ
UA
RE
BR
AS
S B
AR
ST
OC
K
SC
ALE
: 1
INC
H=
0.5
IN
CH
Figure 36
. PN-32, pr
inte
d ci
rcui
t board
moun
ting b
lock
,
PA
RT
NU
MB
ER
47
BO
OT
M/F
(C
) N
OT
TO S
CA
LE
SO
LD
ER
AB
LE
BA
ND
0.41
0.09
0 1 AP
RO
X.
DIM
EN
SIO
NS
0.15
5D.
PA
RT
NU
MB
ER
8
TH
ER
MIS
TO
R,
0.5
INC
H G
LAS
S P
RO
BE
(C
)
NO
T TO
SC
ALE
Un
00
0.24
5
0.745
PA
RT
NU
MB
ER
40
CO
NN
EC
TO
R,
4-P
IN
MA
LE
(C)
NO
T T
O S
CA
LE
O-R
ING
GR
OO
VE
0-r
ing
siz
e 2
-01
3
7/,6
I.D
. 9/
,6 O
.D.
V,6
W.
Figure 37
. PN
-8,
ther
mist
er (C
); PN
-40,
4-
pin
male co
nnec
tor
(C);
PN-47,connector
boot (C
).
c:---
l!L<
1.75
>
*
.31 1
1/4
Hex
Ln
PA
RT
NU
MB
ER
44
(C)
HIG
H P
RE
SS
UR
E W
AT
ER
PR
OO
F FE
ED
THR
U,
MA
LE,
PLA
ST
IC,
20,0
00 p
si
NO
T TO
SC
ALE
vO
.150
MO
UN
TIN
G D
ET
AIL
PA
RT
NU
MB
ER
45
<C
)C
AB
LE A
SS
EM
BLY
, M
OU
LDE
D
FE
MA
LE W
ITH
24
INC
H C
AB
LE,
0.10
5 IN
CH
DIA
N
OT
TO
SC
ALE -- '"T
r v L.L
U<
1.75
»
|
A .31 Y
PA
RT
NU
MB
ER
46
(C
)C
ON
NE
CT
OR
, F
EM
ALE
, FO
R
0.10
5-IN
CH
DIA
ME
TE
R C
AB
LE
NO
T T
O S
CA
LE
Figu
re 38
. PN-4
4, high-pressure
waterproof feedthrough
(C)
with
mounting detail;
PN-45, mo
ulde
d waterproof co
nnector
and
cabl
e (C);
PN
-46,
mo
ulde
d wa
terp
roof
fe
male
connec
tor
(C).
TO
FLO
W S
EN
SO
R
U 0
.37
5 >
J
II
I I
I
(30)
(3
2.
I T
I I
I I
O
0.03
1
ED
GE
VIE
W O
F R
AIL
(3
3)
ELE
CTR
ON
ICS
CA
RR
IER
AS
SE
MB
LYM
ATE
RIA
L:
STE
EL
(OR
TE
MP
ER
ED
AL
UM
INU
M O
R B
RA
SS
)NOT TO SCALE
O
(30)
(3
2)
I i
O
El
o
n
Figu
re 39
. Electronics
carr
ier
asse
mbly
, PN
-30-
33,
and
41
.195
TO
SE
NS
OR
14"
AD
J. T
O F
IT
100|
UF
/400
V
C20
A+
+10
0|uF
/400
V
C20
B
16.
032
B-1
---V
BO
AR
D
EX
PLA
NA
TIO
N
o
Ter
min
al
Pos
t
TO C
AB
LE H
EA
D
THE
RM
AL
FLO
WM
ETE
R P
RO
BE
EL
EC
TR
ON
ICS
LA
YO
UT
NO
T T
O S
CA
LE
Figu
re 40
. Probe
elec
tron
ics
layo
ut.
AD
D 2
SLO
TS
0.
05 W
IDE
, 0.
07
DE
EP
, S
PA
CE
D A
T 1
80°
fO
-0.7
70 D
OR
IGIN
AL F
LAN
GE
(M
OD
IFIE
D A
S S
HO
WN
)
0.87
0
2 E
QU
ALLY
SP
AC
ED
HO
LES
37 D
RIL
L (0
.104 D
IA.)
O
N
0.7
70 D
IA.
CIR
CLE
OR
IGIN
AL F
LAN
GE
(r
em
ove
to i
nsu
lato
r as
sh
ow
n)
0.2
0
PA
RT
NU
MB
ER
42
(C
)M
OD
IFIE
D C
ON
NE
CT
OR
M
S-3
110
F 10
-6 S
(S
OC
KE
T)
NO
T TO
SC
ALE
Fig
ure
41
. P
N-4
2,
mo
dif
icat
ion
to
co
nn
ecto
r M
S31
10F
10-6
S.
Start in center and thread resistance wire in both directions
of insulation coated resistance wire
\ _, ^ .^ _ i^ ̂ .
I '
Fill groove with waterproof, insulating sealer keeping surface of sealer within
' e diameter of the heater frame
Part Number 13 or 13A
\Place HEATER FRAME on ASSEMBLY JIGwhile winding the reistance wire. Then,
with the HEATER still attached to the
ASSEMBLY JIG, insert the HEATER
into the TOP FLOW TUBE end carefully
remove the ASSEMBLY JIG, leaving the
HEATER FRAME in the TOP FLOW TUBE
NOT TO SCALE
Heater Frame
Heater assemblyjig for wiring heater frame
Part Number 28 or 28A
Figure 42. Assembly of heater (13 or 13A) using heater assembly jig (28 or 28A).
63
Pretinned metal ring on thermistor PART NO. 8
Attach thin insulated wires to thermistor leads and cover with thin wall insulation tubing.
-Pretin inside of thermistor post; sweat solder thermistor into post.
PART NO. I
NOT TO SCALE
Bottom thermistor post only, solder one thermistor lead to a notch on inside of post.
Other lead will be soldered to bottom of feed through connector.
Figure 43. Assembly of thermistor (8) and post (11)
64
Groove for heater wire
Wire
Solder together and insulate with silicone sealer _
Heater
Part Number 13 or 13A
0-ring
Part Number 14 or 14A
Bottom flow tube
Part Number 15 or15A
NOT TO SCALE
Top flow tube
Part Number 12 or 12A
Groove for bottom thermistor wire
Solder end of heater wire to top flow tube in notch filed in the cable groove. Zinc chloride solder flux is useful for soldering the heater wire to the stainless steel, but all traces of the residual zinc chloride must be flushed from the parts after soldering.
Round to make a smooth transitionfrom cone to cylinder, about a 3-inch radius
Figure 44. Assembly of flow sensor tube parts
65
TR
IGG
ER
AM
P-
VC
O A
MP
and
DR
IVE
R-
12 V
.P.S
.
TH
IS C
ON
NE
CT
S T
O R
IGH
T
EN
D O
F B
-BO
AR
D
TH
IS C
ON
NE
CT
S T
O L
EFT
E
ND
OF
A-B
OA
RD
EN
ER
GY
S
EN
SO
R
ST
OR
AG
E
ALL D
IOD
ES
AR
E
1N
91
4 U
NLE
SS
OT
HE
RW
ISE
D
ES
IGN
AT
ED
[43
1
AR
E P
AR
T N
UM
BE
RS
*
TE
MP
ER
AT
UR
E
ST
AB
LE
C
OM
PO
NE
NT
S
Figu
re 45
. Sc
hema
tic
of probe
electronics, A-
and
B-boards.
*
"*
3s
I 2-
^N.
^
m
JUM
PE
R
TOP
.
HV
12v T
S
EX
PLA
NA
TIO
N
O T
ER
MIN
AL
PO
ST
fcg o
ifc
* ^
* *
s H
5l3
-§ I
° §
i
S i
S°
2?
*C
OM
PO
NE
NT
SID
E
r II
I I
Ulll
lSill
II
I I
II
ly^r
HV
24
v(+
30vZ
enor)
TR
IG.
SIG
'L
CO
M
CO
ND
UC
TOR
S
IDE
GR
OU
ND
ALL
HO
LES
FO
R C
OM
PO
NE
NT
S A
RE
# 6
0 D
RIL
L#
31
D
RIL
L H
OLE
B
OT
H
EN
DS
A-B
OA
RD
TRIG
. A
MP
/SIG
'L A
MP
/12V
P.S
.TO
SC
ALE
Fig
ure
46
. A
cir
cu
it
boar
d,
prob
e ele
ctr
on
ics.
F/K
-
HV
-
A/1
2v
B/S
-
C/C
OM
-
EX
PLA
NA
TIO
N
O T
ER
MIN
AL
PO
ST
r»
to
in ^
t-
t-
OJ
CM C
M(J
(J
Q
DC
DC
8 S
CC
(J
I H
ill
I ii
i
f tt
«
I
Ou.
S£
~
5 5!
^ z
oi
*t
co
« r.
o
r (J ^ Q
CN
rooc
«-
(j
CO
MP
ON
EN
T
SID
E
* H
V
< 1
2v
-*
T
* S
*«
C
BO
TT
OM
00
GR
OU
ND
CO
ND
UC
TO
R
SID
E
AL
L H
OLE
S F
OR
CO
MP
ON
EN
TS
AR
E
#60 D
RIL
L#31
DR
ILL
HO
LE
BO
TH
E
ND
S
B-B
OA
RD
SC
R/S
IG'L
AM
P/6
V P
.S./V
CO
TO S
CA
LE
Figu
re 47
. B
circuit
boar
d, probe
elec
tronics.
EA
TEH
V
OLT
AG
E
*
BN
C C
ON
NE
CT
OR
V
GR
OU
ND
| n"|
=
D
15S
, C
ON
NE
CT
OR
[n
]> =
N
IM C
ON
NE
CT
OR
ALL
DIO
DE
S A
RE
IN
914
UN
LES
S O
TH
ER
WIS
E N
DTI
©
CO
NT
RO
L IS
ON
FR
ON
T P
AN
El
0
CO
NT
RO
L IS
SC
RE
WD
RIV
ER
AD
JUS
TA
BLE
SC
HE
MA
TIC
OF
SU
RFA
CE
MO
DU
LE O
F T
HE
RM
AL-
PU
LSE
FLO
WM
ETE
R
Figu
re 48
. Sc
hema
tic
of su
rfac
e mo
dule
electronics.
RE
AR
P
AN
EL
|ZB
>H
V-
AC
PO
WE
R
FLO
W
HV
AD
JUS
TM
EN
T
"0"
AD
JUS
TM
EN
T
//
HV
RE
AD
Y
PU
LSE
-TR
IGG
ER
REF
PU
LSE
A
DJU
ST
ME
NT
PR
OB
E S
IGN
AL
AD
JUS
TM
EN
T
HV
TE
ST
SIG
NA
L TE
ST
RE
CO
RD
ER
TE
ST
LAY
OU
T D
IAG
RA
M O
FT
HE
RM
AL-
PU
LSE
FLO
WM
ET
ER
SU
RF
AC
E M
OD
ULE
Fig
ure
49
. E
lect
ron
ic
com
pone
nt
layout
for
surf
ace
mod
ule.
