Geokon 4700 User manual

Instruction Manual
Model 4700
VW Temperature Gage
No part of this instruction manual may be reproduced, by any means, without the written consent of Geokon, Inc.
The information contained herein is believed to be accurate and reliable. However, Geokon, Inc. assumes no responsibility for
errors, omissions or misinterpretation. The information herein is subject to change without notification.
Copyright © 1984, 2004 by Geokon, Inc.
(Doc Rev C, 9/07)

Warranty Statement
Geokon, Inc. warrants its products to be free of defects in materials and workmanship, under normal use and
service for a period of 13 months from date of purchase. If the unit should malfunction, it must be returned to the
factory for evaluation, freight prepaid. Upon examination by Geokon, if the unit is found to be defective, it will
be repaired or replaced at no charge. However, the WARRANTY is VOID if the unit shows evidence of having
been tampered with or shows evidence of being damaged as a result of excessive corrosion or current, heat,
moisture or vibration, improper specification, misapplication, misuse or other operating conditions outside of
Geokon's control. Components which wear or which are damaged by misuse are not warranted. This includes
fuses and batteries.
Geokon manufactures scientific instruments whose misuse is potentially dangerous. The instruments are intended
to be installed and used only by qualified personnel. There are no warranties except as stated herein. There are no
other warranties, expressed or implied, including but not limited to the implied warranties of merchantability and
of fitness for a particular purpose. Geokon, Inc. is not responsible for any damages or losses caused to other
equipment, whether direct, indirect, incidental, special or consequential which the purchaser may experience as a
result of the installation or use of the product. The buyer's sole remedy for any breach of this agreement by
Geokon, Inc. or any breach of any warranty by Geokon, Inc. shall not exceed the purchase price paid by the
purchaser to Geokon, Inc. for the unit or units, or equipment directly affected by such breach. Under no
circumstances will Geokon reimburse the claimant for loss incurred in removing and/or reinstalling equipment.
Every precaution for accuracy has been taken in the preparation of manuals and/or software, however,
Geokon, Inc. neither assumes responsibility for any omissions or errors that may appear nor assumes
liability for any damages or losses that result from the use of the products in accordance with the
information contained in the manual or software.

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TABLE of CONTENTS
1. Theory of Operation..............................................................................................................................................1
2. Installation.............................................................................................................................................................1
3. Readout Procedures...............................................................................................................................................1
4. Data Reduction......................................................................................................................................................1
6. Specifications ........................................................................................................................................................2
Figure 1. Typical Calibration Sheet...................................................................................................................3
Appendix A:..............................................................................................................................................................4
APPENDIX B - HIGH-TEMPERATURE THERMISTOR LINEARIZATION......................................................5

1. Theory of Operation
The theory of operation is described in the Model 4700 brochure.
2. Installation
The Model 4700 Vibrating Wire Temperature Sensor can be installed inside boreholes, buried in fill, or cast
inside concrete. They are fully waterproof. No particular requirements are needed. Preliminary readings should be
taken to ensure that the sensor is functioning properly. Most models incorporate a thermistor that can be used as a
check on the vibrating wire readout.
3. Readout Procedures
Connect the black and red leads to the GK-401, GK-403 or GK-404 VW Readout Box and read on channel B. If
the GK-403 Readout Box, GK 404 Readout Box or Micro-10 Datalogger is used, the thermistor readout can be
displayed directly in °C. If a GK-401 Readout Box is used, the thermistor can be read on the green and white
conductors using a digital ohmmeter in conjunction with the conversion Table in Appendix A. Allowance for
cable resistance may be necessary (22 gage cable has a resistance of 20Ω/300 meters).
4. Data Reduction
The temperature (T) is given by the formula:
T = G (R0–R1)in degrees centigrade
Where: R0is the initial reading on channel B at 0°C
R1is the subsequent reading on channel B
Gis the gage factor
A typical calibration sheet showing the gage factor is given on page 3.
5. Trouble Shooting _______________________________________________
Maintenance and trouble shooting of vibrating wire temperature sensors are confined to periodic checks of cable
connections and maintenance of terminals. The transducers themselves are sealed and cannot be opened for
inspection.
•A normal resistance between black and red conduction is 180Ω± 5Ωplus cable resistance (20Ω/300m).
•A normal resistance between white and green conduction depends on the temperature (see table on page 4).
If the resistance deviates from the norms, inspect the cable for damage.

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6. Specifications
Range Standard: –20°C to +80°C
Optional: any 200°C span from –200°C to +200°C.
Resolution 0.04°C (approximate)
Accuracy ±0.5% F.S.
Frequency Range 1400 – 3500 Hz
Diameter 19mm
Length 125mm
Weight 115gm
Cable 4 conductor shielded .22awg

3
Figure 1. Typical Calibration Sheet.

4
Appendix A:
Thermistor Linearization using Steinhart and Hart Log Equation
Tech Memo 91-03 Doc Rev 6-94, Geokon, Inc.
Thermistor Type: YSI 44005, Dale #1C3001-B3, Alpha #13A3001-B3
Basic Equation: TA B LnR C LnR
=
++
−
1273 2
3
()() .
where: T=Temperature in °C.
LnR =Natural Log of Thermistor Resistance
A=1.4051 ×10-3
B=2.369 ×10-4
C=1.019 ×10-7
Note: Coefficients calculated over -50
° to +150 ° C. span.
Resistance versus Temperature Table
Ohms Temp Ohms Temp Ohms Temp Ohms Temp Ohms Temp
201.1K -50 16.60K -10 2417 +30 525.4 +70 153.2 +110
187.3K -49 15.72K -9 2317 31 507.8 71 149.0 111
174.5K -48 14.90K -8 2221 32 490.9 72 145.0 112
162.7K -47 14.12K -7 2130 33 474.7 73 141.1 113
151.7K -46 13.39K -6 2042 34 459.0 74 137.2 114
141.6K -45 12.70K -5 1959 35 444.0 75 133.6 115
132.2K -44 12.05K -4 1880 36 429.5 76 130.0 116
123.5K -43 11.44K -3 1805 37 415.6 77 126.5 117
115.4K -42 10.86K -2 1733 38 402.2 78 123.2 118
107.9K -41 10.31K -1 1664 39 389.3 79 119.9 119
101.0K -40 9796 0 1598 40 376.9 80 116.8 120
94.48K -39 9310 +1 1535 41 364.9 81 113.8 121
88.46K -38 8851 2 1475 42 353.4 82 110.8 122
82.87K -37 8417 3 1418 43 342.2 83 107.9 123
77.66K -36 8006 4 1363 44 331.5 84 105.2 124
72.81K -35 7618 5 1310 45 321.2 85 102.5 125
68.30K -34 7252 6 1260 46 311.3 86 99.9 126
64.09K -33 6905 7 1212 47 301.7 87 97.3 127
60.17K -32 6576 8 1167 48 292.4 88 94.9 128
56.51K -31 6265 9 1123 49 283.5 89 92.5 129
53.10K -30 5971 10 1081 50 274.9 90 90.2 130
49.91K -29 5692 11 1040 51 266.6 91 87.9 131
46.94K -28 5427 12 1002 52 258.6 92 85.7 132
44.16K -27 5177 13 965.0 53 250.9 93 83.6 133
41.56K -26 4939 14 929.6 54 243.4 94 81.6 134
39.13K -25 4714 15 895.8 55 236.2 95 79.6 135
36.86K -24 4500 16 863.3 56 229.3 96 77.6 136
34.73K -23 4297 17 832.2 57 222.6 97 75.8 137
32.74K -22 4105 18 802.3 58 216.1 98 73.9 138
30.87K -21 3922 19 773.7 59 209.8 99 72.2 139
29.13K -20 3748 20 746.3 60 203.8 100 70.4 140
27.49K -19 3583 21 719.9 61 197.9 101 68.8 141
25.95K -18 3426 22 694.7 62 192.2 102 67.1 142
24.51K -17 3277 23 670.4 63 186.8 103 65.5 143
23.16K -16 3135 24 647.1 64 181.5 104 64.0 144
21.89K -15 3000 25 624.7 65 176.4 105 62.5 145
20.70K -14 2872 26 603.3 66 171.4 106 61.1 146
19.58K -13 2750 27 582.6 67 166.7 107 59.6 147
18.52K -12 2633 28 562.8 68 162.0 108 58.3 148
17.53K -11 2523 29 543.7 69 157.6 109 56.8 149
55.6 150

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APPENDIX B - HIGH-TEMPERATURE THERMISTOR LINEARIZATION
High Temperature Thermistor Linearization using SteinHart-Hart Log Equation
Thermistor Type: Thermometrics BR55KA822J Basic Equation: 2.273
)()( 13− ++
=LnRCLnRBA T

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Where: T=Temperature in °C LnR =Natural Log of Thermistor Resistance
A=1.02569 ×10-3 B=2.478265 ×10-4 C=1.289498 ×10-7
Temp R
(ohms)
LnR LnR3Calculated
Temp Diff FS Error Temp R
(ohms)
LnR LnR3Calculated
Temp
Diff FS
Error
-30 113898 11.643 1578.342 -30.17 0.17 0.06 120 407.62 6.010 217.118 120.00 0.00 0.00
.-25 86182 11.364 1467.637 -25.14 0.14 0.05 125 360.8 5.888 204.162 125.00 0.00 0.00
-20 65805 11.094 1365.581 -20.12 0.12 0.04 130 320.21 5.769 191.998 130.00 0.00 0.00
-15 50684.2 10.833 1271.425 -15.10 0.10 0.03 135 284.95 5.652 180.584 135.00 0.00 0.00
-10 39360 10.581 1184.457 -10.08 0.08 0.03 140 254.2 5.538 169.859 140.01 -0.01 0.00
-5 30807.4 10.336 1104.068 -5.07 0.07 0.02 145 227.3 5.426 159.773 145.02 -0.02 -0.01
0 24288.4 10.098 1029.614 -0.05 0.05 0.02 150 203.77 5.317 150.314 150.03 -0.03 -0.01
5 19294.6 9.868 960.798 4.96 0.04 0.01 155 183.11 5.210 141.428 155.04 -0.04 -0.01
10 15424.2 9.644 896.871 9.98 0.02 0.01 160 164.9 5.105 133.068 160.06 -0.06 -0.02
15 12423 9.427 837.843 14.98 0.02 0.01 165 148.83 5.003 125.210 165.08 -0.08 -0.03
20 10061.4 9.216 782.875 19.99 0.01 0.00 170 134.64 4.903 117.837 170.09 -0.09 -0.03
25 8200 9.012 731.893 25.00 0.00 0.00 175 122.1 4.805 110.927 175.08 -0.08 -0.03
30 6721.54 8.813 684.514 30.01 -0.01 0.00 180 110.95 4.709 104.426 180.07 -0.07 -0.02
35 5540.74 8.620 640.478 35.01 -0.01 0.00 185 100.94 4.615 98.261 185.10 -0.10 -0.04
40 4592 8.432 599.519 40.02 -0.02 -0.01 190 92.086 4.523 92.512 190.09 -0.09 -0.03
45 3825.3 8.249 561.392 45.02 -0.02 -0.01 195 84.214 4.433 87.136 195.05 -0.05 -0.02
50 3202.92 8.072 525.913 50.01 -0.01 -0.01 200 77.088 4.345 82.026 200.05 -0.05 -0.02
55 2693.7 7.899 492.790 55.02 -0.02 -0.01 205 70.717 4.259 77.237 205.02 -0.02 -0.01
60 2276.32 7.730 461.946 60.02 -0.02 -0.01 210 64.985 4.174 72.729 210.00 0.00 0.00
65 1931.92 7.566 433.157 65.02 -0.02 -0.01 215 59.819 4.091 68.484 214.97 0.03 0.01
70 1646.56 7.406 406.283 70.02 -0.02 -0.01 220 55.161 4.010 64.494 219.93 0.07 0.02
75 1409.58 7.251 381.243 75.01 -0.01 0.00 225 50.955 3.931 60.742 224.88 0.12 0.04
80 1211.14 7.099 357.808 80.00 0.00 0.00 230 47.142 3.853 57.207 229.82 0.18 0.06
85 1044.68 6.951 335.915 85.00 0.00 0.00 235 43.673 3.777 53.870 234.77 0.23 0.08
90 903.64 6.806 315.325 90.02 -0.02 -0.01 240 40.533 3.702 50.740 239.69 0.31 0.11
95 785.15 6.666 296.191 95.01 -0.01 0.00 245 37.671 3.629 47.788 244.62 0.38 0.13
100 684.37 6.528 278.253 100.00 0.00 0.00 250 35.055 3.557 45.001 249.54 0.46 0.16
105 598.44 6.394 261.447 105.00 0.00 0.00 255 32.677 3.487 42.387 254.44 0.56 0.19
110 524.96 6.263 245.705 110.00 0.00 0.00 260 30.496 3.418 39.917 259.34 0.66 0.23
115 461.91 6.135 230.952 115.00 0.00 0.00