Geokon GK-404 User manual

©2019, GEOKON. All rights reserved.
Document Revision: O | Release date: 11/15/19
Model GK-404
Vibrating Wire Readout
Instruction Manual

WARRANTY STATEMENT
GEOKON 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 specifi-
cation, misapplication, misuse or other operating conditions outside of GEOKON's
control. Components that wear or 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 merchant-
ability and of fitness for a particular purpose. GEOKON 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 instal-
lation or use of the product. The buyer's sole remedy for any breach of this agreement
by GEOKON or any breach of any warranty by GEOKON shall not exceed the purchase
price paid by the purchaser to GEOKON 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 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.
No part of this instruction manual may be reproduced, by any means, without the written consent of GEOKON. The
information contained herein is believed to be accurate and reliable. However, GEOKON assumes no responsibility
for errors, omissions or misinterpretation. The information herein is subject to change without notification.
The GEOKON® wordmark and logo are registered trademarks with the United States Patent and Trademark Office.

I
TABLE OF CONTENTS
1. INTRODUCTION............................................................................................................................................1
2. INITIAL SETUP...............................................................................................................................................2
2.1 ACCESSORIES ........................................................................................................................................2
2.2 CONNECTING A SENSOR.............................................................................................................3
2.3 CONNECTING A LOAD CELL......................................................................................................3
3. OPERATION.......................................................................................................................................................4
3.1 POS (POSITION) BUTTON............................................................................................................4
3.2 MODE BUTTON......................................................................................................................................4
3.3 CONFIGURATION (CFG) BUTTON .........................................................................................4
3.4 DEFAULT SETTINGS .........................................................................................................................5
4. MAINTENANCE.............................................................................................................................................6
4.1 LOW BATTERY INDICATION AND AUTO-OFF............................................................6
4.2 BATTERY REPLACEMENT ............................................................................................................6
4.3 CLEANING ..................................................................................................................................................6
4.4 CALIBRATION .........................................................................................................................................6
5. TROUBLESHOOTING ..............................................................................................................................7
6. LIMITS OF LIABILITY.............................................................................................................................8
APPENDIX A. SPECIFICATIONS ......................................................................................................9
A.1 VIBRATING WIRE READOUT ....................................................................................................9
A.2 TEMPERATURE READOUT ..........................................................................................................9
A.3 PHYSICAL...................................................................................................................................................9
A.4 TRANSDUCER PLUG PIN OUT ................................................................................................9
APPENDIX B. THERMISTOR TEMPERATURE DERIVATION....................... 10
B.1 THERMISTOR RESISTANCE FOR 3KΩ ......................................................................... 10
B.2 THERMISTOR RESISTANCE FOR 8.2KΩ .................................................................... 11
B.3 THERMISTOR RESISTANCE FOR 10KΩ...................................................................... 12

II
FIGURES
FIGURE 1: LEMO CONNECTOR ........................................................................................2
FIGURE 2: NECK STRAP CONNECTOR ............................................................................2
FIGURE 3: CONNECTOR ON GK-404 ...............................................................................2
FIGURE 4: DOWNWARD-POINTING CONNECTOR .........................................................3
FIGURE 5: NECK STRAP CONNECTIONS .........................................................................3

III
TABLES
TABLE 1: LOAD CELL WIRING DIAGRAM ....................................................................... 3
TABLE 2: POSITION SPECIFICATIONS.............................................................................. 4
TABLE 3: VIBRATING WIRE READOUT ............................................................................ 9
TABLE 4: TEMPERATURE READOUT ................................................................................ 9
TABLE 5: PHYSICAL SPECIFICATIONS ............................................................................. 9
TABLE 6: TRANSDUCER PLUG PINOUT........................................................................... 9
TABLE 7: THERMISTOR RESISTANCE FOR 3KΩ........................................................... 10
TABLE 8: THERMISTOR RESISTANCE FOR 8.2KΩ........................................................ 11
TABLE 9: THERMISTOR RESISTANCE FOR 10KΩ......................................................... 12

IV
EQUATIONS
EQUATION 1: THERMISTOR RESISTANCE FOR 3KΩ.....................................................10
EQUATION 2: THERMISTOR RESISTANCE FOR 8.2KΩ..................................................11
EQUATION 3: THERMISTOR RESISTANCE FOR 10KΩ...................................................12

MODEL GK-404 VIBRATING WIRE READOUT | INTRODUCTION | 1
1. INTRODUCTION
The Model GK-404 Vibrating Wire Readout is a portable, low-power, handheld
readout unit that is capable of operating for more than 20 hours continuously on
two AA batteries. It is designed for the readout of all Geokon vibrating wire
gauges and transducers, and is capable of displaying the reading in either digits,
frequency (Hz), period (μs), or microstrain (με). The GK-404 also displays the
temperature of the transducer (embedded thermistor) with a resolution of 0.1 °C.

2| INITIAL SETUP | GEOKON
2. INITIAL SETUP
2.1 ACCESSORIES
The GK-404 is sold with the following accessories:
■GK-404-1 flying leads
■Carrying case
■Nylon strap for the carrying case
■Neck strap for the GK-404
Before use, attach the flying leads to the GK-404 as follows:
1. Align the red circle on the silver Lemo connector on the flying leads with the
red line on the connector on the top of the GK-404.
2. Insert the Lemo connector into the GK-404 until it locks into place (see
Figure 1).
3. Remove the flying leads before storing the GK-404 in the carrying case.
To connect the nylon strap to the carrying case, clip both ends of the strap onto
the plastic loops on the sides of the case.
Connect the neck strap to the GK-404 as follows:
1. Locate the plastic connector on the neck strap (see the figure below).
FIGURE 2: Neck Strap Connector
2. Place the larger circular hole onto the plastic nub on the back of the GK-404,
with the bottom of the connector to the right (see the figure below).
FIGURE 3: Connector on GK-404
3. Slide the connector all the way to the right, so that the nub on the back of
the GK-404 locks into the smaller hole of the connector.
4. Turn the connector clockwise until the bottom of the connector is pointing
down (see the figure below).
FIGURE 1: Lemo Connector to GK-404

MODEL GK-404 VIBRATING WIRE READOUT | INITIAL SETUP | 3
FIGURE 4: Downward-Pointing Connector
Snap together the twin connectors located at the strap ends (see the figure
below).
FIGURE 5: Neck Strap Connections
2.2 CONNECTING A SENSOR
Attach the GK-404-1 flying leads to the bare leads of a GEOKON vibrating wire
sensor by connecting each of the clips on the leads to the matching colors of the
sensor conductors, with blue representing the bare shield wire.
GEOKON makes patch cables that enable the GK-404 to read sensors with
connectors attached to the readout cable.
2.3 CONNECTING A LOAD CELL
If a load cell cable has a readout cable connector attached, the GK-404 can
easily connect to it using a patch cable provided by GEOKON.
If the load cell cable does not have a connector, the leads of the load cell may be
connected directly to the flying leads from the GK-404. The individual leads can
be identified as shown in the wiring diagram in Table 1 below.
Each sensor is read in turn by connecting either the red or black clip to the lead
marked common. The black or red clip must be connected to the leads marked
#1, #2, #3, etc. The blue clip should be connected to the cable shield wire, and
the green and white clips to the cable leads marked thermistor.
1White's black and Green wires are switched on Geokon three gauge VW load cells prior to serial number 3313.
TABLE 1: Load Cell Wiring Diagram
10‑pin Bulkhead
PT06A‑12‑10P Function Three Gauge VW Load Cell Geokon Purple Cable
Four Gauge VW Load Cell
Geokon Purple Cable
Six Gauge VW Load Cell
Geokon Orange Cable
A Gauge #1 Red Red Red
B Gauge #2 Red's Black Red's Black Red's Black
C Gauge #3 White White White
D Gauge #4 NC White's Black White's Black
EGauge#5NC NC Green
F Gauge #6 NC NC Green's Black
G Shield All Shields All Shields All Shields
H Common White's Black¹ Green Blue
J Thermistor Green¹ Blue Yellow
K Thermistor Green's Black Blue's Black Yellow's Black

4| OPERATION | GEOKON
3. OPERATION
To turn on the GK-404 on, press the On/Off button on the front panel of the unit.
The initial startup screen will be displayed. After approximately one second, the
GK-404 will start taking readings and display them based on the settings of the
Pos and Mode buttons.
The unit display (from left to right) is as follows:
■The current Position, set by the Pos button, displayed as a letter, A - F.
■The current Reading, displayed as a numeric value, followed by the unit of
measure (set by the Mode button).
■Temperature reading of the attached gauge in degrees Celsius.
The GK-404 will continue to take measurements and display readings until the
unit is turned off, either manually, or if enabled, by the Auto-Off timer. See
Section 3.3 for information on the Auto-Off timer. To turn off the GK-404
manually, press and hold the On/Off button until Saving Settings is displayed,
then release the button. All user settings are stored at shut off and will be
restored the next time the GK-404 is turned on.
3.1 POS (POSITION) BUTTON
Use the Pos button to change the GK-404 pluck settings. Each Position setting
(A-F) has different preprogrammed parameters that are optimized for certain
instruments. Each option also has different scaling and processing
characteristics. The table below details the correct position to use with the
various models sold by GEOKON.
TABLE 2: Position Specifications
3.2 MODE BUTTON
Pressing the Mode button will select the format of the vibrating wire reading.
The available options are Dg (digits), Hz (hertz),
μ S (period), and με (microstrain).
Only positions C, D, and E support the
με microstrain format.
3.3 CONFIGURATION (CFG) BUTTON
Pressing the Cfg button will cause the GK-404 to enter the Configuration Menu.
The LCD screen will display:
GK-404 verX.XX
Config Menu
From this menu, several GK-404 operating parameters may be set. Use the Pos
button to select the various parameters and the Mode button to select each
parameter's options. Press Cfg twice at any time to exit the Configuration Menu
Position A B C D E F
Use with
Geokon Models: All
4300BX 4400
4500 4600 4700
4800 4900
4000 4200 4100 4300EX
Mode 1: Dg με Dg
Units: Digits μStrain(ε) Digits
Calculation: F210-3 F210-34.062 F210-33.304 F210-30.39102 F210-3
Mode 2: Hz
Units: Hertz
Calculation: F = Frequency in Hertz
Mode 3: μS
Units: μSec
Calculation: T = Period (1/F) in μSec
Frequency Sweep: (Hz) 450‑6000 1500‑3500 450‑1200 1500‑3500 2500‑6000

MODEL GK-404 VIBRATING WIRE READOUT | OPERATION | 5
and return to the Readings Screen. Parameters available from the Configuration
Menu are as follows:
BACKLIGHT:
Press Mode to turn the LCD backlight on or off.
BATTERY VOLTAGE:
This is a bar graph display of the power remaining in the two 1.5V AA cells, with
F for FULL and E for EMPTY. The GK-404 is capable of continuous operation for
greater than 20 hours on a fresh set of batteries.
CONTRAST:
Press the Mode button to adjust the contrast of the LCD display in 10%
increments.
AUTO-OFF:
Press the Mode button to select automatic shutoff after five minutes, 15
minutes, or 30 minutes. The Auto-Off may be disabled so that the GK-404 will
only shut off if the front panel On/Off button is pressed. The Auto-Off will
activate only if no front panel buttons are pressed for the specified amount of
time. The timer will reset each time a button is pressed. When the GK-404
powers down, all settings are saved to the internal memory, and will restore the
next time the GK-404 is turned on.
Note: The times mentioned above are approximate.
3.4 DEFAULT SETTINGS
Factory default settings can be restored by pressing and holding the Cfg and
Pos buttons when powering on the GK-404. The factory default settings are:
Position: B
Mode: Dg
Backlight: Off
Contrast: 50%
Power-off Time: Five minutes

6| MAINTENANCE | GEOKON
4. MAINTENANCE
4.1 LOW BATTERY INDICATION AND AUTO-OFF
The GK-404 continuously monitors the status of the two 1.5V AA cells. When
their combined voltage drops to 2V, the message Batteries Low is displayed on
the screen. A fresh set of 1.5V AA batteries should be installed at this point. If
the battery voltage drops to 1.8V, the message REPLACE BATTERIES will be
displayed on the screen; the GK-404 will then shut off. All settings are still saved
in the internal nonvolatile memory.
4.2 BATTERY REPLACEMENT
Alkaline batteries are the best choice for use in the GK-404. A set of two 1.5V AA
batteries are installed in the GK-404 at the factory. To replace the batteries, use a
#1 Phillips screwdriver to remove the battery compartment cover located at the
back of the readout. Install a new set of batteries following the polarities
indicated inside the battery compartment. Reinstall the battery compartment
cover.
Never use two different types of batteries or mix old batteries with new. This
could cause batteries to leak and permanently damage the readout. Although
alkaline batteries are highly recommended, carbon zinc A batteries can be used.
4.3 CLEANING
A clean cloth can be used to wipe down the GK-404 Readout. No solvents
should be used as they may damage the case of the readout.
4.4 CALIBRATION
The readout should be sent periodically (every 12 months) to the manufacturer
for inspection, cleaning, and calibration. A nominal fee will be charged for the
service, but it is highly recommended.

MODEL GK-404 VIBRATING WIRE READOUT | TROUBLESHOOTING | 7
5. TROUBLESHOOTING
Listed below are a few commonly experienced problems and remedial action.
Contact the factory should a problem arise not explained herein.
SYMPTOM: UNIT WILL NOT COME ON
□Internal batteries are either dead or installed backwards.
SYMPTOM: VIBRATING WIRE GAUGE MEASUREMENT SHOWS
DASHES
□Check alligator clip connections to vibrating wire gauge leads. if okay,
check gauge with ohmmeter. It should read between 90 and 180 ohms. If
gauge resistance is okay, check readout with another gauge. If it still does
not work, consult the factory to schedule return and repair of readout.
SYMPTOM: VIBRATING WIRE GAUGE READING UNSTABLE
□Improper position selected. Verify gauge model number against the
recommended setting (see Table 2 in Section 3.1). If position setting is
correct, the gauge is either marginal or there may be a strong source of
electromagnetic interference nearby.
SYMPTOM: THERMISTOR MEASUREMENT SHOWS DASHES
□Check alligator clip connections to thermistor leads. If okay, check
thermistor with ohmmeter. It should read between 10K ohms and 2.4K
ohms (0 to +30 degrees Celsius). If the thermistor checks out okay, consult
factory to schedule repair of readout. Note: dashes will display if no
Thermistor is connected.
SYMPTOM: DISPLAY SHOWS WEIRD CHARACTERS
□Switch the GK-404 to the ON setting while pushing the Cfg and Pos
buttons at the same time, to restore the unit to its factory default settings.

8| LIMITS OF LIABILITY | GEOKON
6. LIMITS OF LIABILITY
The GK-404 Vibrating Wire Readout has been developed specifically for use with
GEOKON vibrating wire gauges and, as such, GEOKON assumes no responsibility
for its use with other systems. Every effort has been made to ensure reliable
operation, but the user must be aware that there is no warranty against
uninterrupted or trouble-free operation. For the user conducting particularly
unusual or sensitive analysis, or for those not familiar with vibrating wire gauge
data processing, it is recommended that the problems be double checked using
another measurement system.
In addition, the readout is provided as is and GEOKON assumes no responsibility
as to results, performance, or interpretation associated with the GK-404
vibrating wire readout. Warranty shall cover parts (except batteries) and labor for
a period of one year from the date of purchase. In addition, there is a one-month
grace period to the warranty for a total of 13 months.
GEOKON reserves the right to revise this publication and/or readout from time to
time with no obligation to notify users of these changes.
Overall, GEOKON is not liable for any claims, injuries, or damages caused directly
or indirectly by the proper or improper use of the GK-404 Vibrating wire readout,
beyond the purchase price of the readout.

MODEL GK-404 VIBRATING WIRE READOUT | SPECIFICATIONS | 9
APPENDIX A. SPECIFICATIONS
A.1 VIBRATING WIRE READOUT
TABLE 3: Vibrating Wire Readout
A.2 TEMPERATURE READOUT
See Appendix B for more information.
TABLE 4: Temperature Readout
A.3 PHYSICAL
TABLE 5: Physical Specifications
A.4 TRANSDUCER PLUG PIN OUT
TABLE 6: Transducer Plug Pinout
Excitation Range: 400 Hz to 6000 Hz, 5‑volt square wave
Measurement Resolution: 0.1 Hz, 0.1 μS, 0.1 Digit
Measurement Accuracy: ±0.025% of Full Scale (6000 Hz)
Sensor Type: Thermistor, YSI 44005, Dale #1C3001‑B3, Alpha #13A3001‑B3
Sensor Accuracy: 0.5 Celsius
Measurement Range: 20 to 50 Celsius
Measurement Resolution: 0.1 Celsius
Measurement Accuracy: ±1.0% of Full Scale
Display: 16 columns x two lines LCD
Dimensions: 120 mm (4.72") x 65 mm (2.56") x 22 mm (0.87")
Weight: Approx. 145 grams (5.1 ounces) with two AA alkaline batteries installed
Temperature Range: -20 to +50 Celsius
Battery: Two AA 1.5 volt alkaline.
Operating Time: Minimum 24 hours continuous at +25º Celsius
Pin # on 5‑pin LEMO
(HGG.OB.305.CLLP) Wire Color Flying Leads Alligator Clip Boot Color Description
1 Red Red VW Gauge+
2BlackBlackVWGauge-
3 White White Thermistor+
4 Green Green Thermistor-
5 Bare Blue DrainWire

10 | THERMISTOR TEMPERATURE DERIVATION | GEOKON
APPENDIX B. THERMISTOR TEMPERATURE
DERIVATION
B.1 THERMISTOR RESISTANCE FOR 3KΩ
Thermistor Types:
■YSI 44005, Dale #1C3001-B3, Alpha #13A3001-B3
■Honeywell 192-302LET-A01
Resistance to Temperature Equation:
EQUATION 1: Thermistor Resistance for 3kΩ
Where:
T= Temperature in °C
LnR = Natural Log of Thermistor Resistance
A= 1.4051 x 10-3
B= 2.369 x 10-4
C= 1.019 x 10-7
Note: Coefficients calculated over the -50 to +150 C span.
TABLE 7: Thermistor Resistance for 3kΩ
T= 1– 273.15
A+B(LnR)+C(LnR3)
Ohms Temp Ohms Temp Ohms Temp Ohms Temp Ohms Temp
201.1K -50 15.72K -9 2221 32 474.7 73 137.2 114
187.3K -49 14.90K -8 2130 33 459.0 74 133.6 115
174.5K -48 14.12K -7 2042 34 444.0 75 130.0 116
162.7K -47 13.39K -6 1959 35 429.5 76 126.5 117
151.7K -46 12.70K -5 1880 36 415.6 77 123.2 118
141.6K -45 12.05K -4 1805 37 402.2 78 119.9 119
132.2K -44 11.44K -3 1733 38 389.3 79 116.8 120
123.5K -43 10.86K -2 1664 39 376.9 80 113.8 121
115.4K -42 10.31K -1 1598 40 364.9 81 110.8 122
107.9K -41 9796 0 1535 41 353.4 82 107.9 123
101.0K -40 9310 1 1475 42 342.2 83 105.2 124
94.48K -39 8851 2 1418 43 331.5 84 102.5 125
88.46K -38 8417 3 1363 44 321.2 85 99.9 126
82.87K -37 8006 4 1310 45 311.3 86 97.3 127
77.66K -36 7618 5 1260 46 301.7 87 94.9 128
72.81K -35 7252 6 1212 47 292.4 88 92.5 129
68.30K -34 6905 7 1167 48 283.5 89 90.2 130
64.09K -33 6576 8 1123 49 274.9 90 87.9 131
60.17K -32 6265 9 1081 50 266.6 91 85.7 132
56.51K -31 5971 10 1040 51 258.6 92 83.6 133
53.10K -30 5692 11 1002 52 250.9 93 81.6 134
49.91K -29 5427 12 965.0 53 243.4 94 79.6 135
46.94K -28 5177 13 929.6 54 236.2 95 77.6 136
44.16K -27 4939 14 895.8 55 229.3 96 75.8 137
41.56K -26 4714 15 863.3 56 222.6 97 73.9 138
39.13K -25 4500 16 832.2 57 216.1 98 72.2 139
36.86K -24 4297 17 802.3 58 209.8 99 70.4 140
34.73K -23 4105 18 773.7 59 203.8 100 68.8 141
32.74K -22 3922 19 746.3 60 197.9 101 67.1 142
30.87K -21 3748 20 719.9 61 192.2 102 65.5 143
29.13K -20 3583 21 694.7 62 186.8 103 64.0 144
27.49K -19 3426 22 670.4 63 181.5 104 62.5 145
25.95K -18 3277 23 647.1 64 176.4 105 61.1 146
24.51K -17 3135 24 624.7 65 171.4 106 59.6 147
23.16K -16 3000 25 603.3 66 166.7 107 58.3 148
21.89K -15 2872 26 582.6 67 162.0 108 56.8 149
20.70K -14 2750 27 562.8 68 157.6 109 55.6 150
19.58K -13 2633 28 543.7 69 153.2 110
18.52K -12 2523 29 525.4 70 149.0 111
17.53K -11 2417 30 507.8 71 145.0 112
16.60K -10 2317 31 490.9 72 141.1 113

MODEL GK-404 VIBRATING WIRE READOUT | THERMISTOR TEMPERATURE DERIVATION | 11
B.2 THERMISTOR RESISTANCE FOR 8.2KΩ
Thermistor Type: Thermometrics BR55KA822J
Resistance to Temperature Equation:
EQUATION 2: Thermistor Resistance for 8.2kΩ
Where:
T= Temperature in °C
LnR = Natural Log of Thermistor Resistance
A= 1.02569 x 10-3
B= 2.369 x 10-4
C= 1.019 x 10-7
Note: Coefficients calculated over the -50 to +150 C span.
TABLE 8: Thermistor Resistance for 8.2kΩ
T= 1– 273.15
A+B(LnR)+C(LnR3)
Ohms Temp LnR LnR3Calc. Temp Diff F.S. Error Ohms Temp LnR LnR3Calc. Temp Diff F.S. Error
113898 -30 11.643 1578.342 -30.17 0.17 0.06 407.62 120 6.010 217.118 120.00 0.00 0.00
86182 -25 11.364 1467.637 -25.14 0.14 0.05 360.8 125 5.888 204.162 125.00 0.00 0.00
65805 -20 11.094 1365.581 -20.12 0.12 0.04 320.21 130 5.769 191.998 130.00 0.00 0.00
50684.2 -15 10.833 1271.425 -15.10 0.10 0.03 284.95 135 5.652 180.584 135.00 0.00 0.00
39360 -10 10.581 1184.457 -10.08 0.08 0.03 254.2 140 5.538 169.859 140.01 -0.01 0.00
30807.4 -5 10.336 1104.068 -5.07 0.07 0.02 227.3 145 5.426 159.773 145.02 -0.02 -0.01
24288.4 0 10.098 1029.614 -0.05 0.05 0.02 203.77 150 5.317 150.314 150.03 -0.03 -0.01
19294.6 5 9.868 960.798 4.96 0.04 0.01 183.11 155 5.210 141.428 155.04 -0.04 -0.01
15424.2 10 9.644 896.871 9.98 0.02 0.01 164.9 160 5.105 133.068 160.06 -0.06 -0.02
12423 15 9.427 837.843 14.98 0.02 0.01 148.83 165 5.003 125.210 165.08 -0.08 -0.03
10061.4 20 9.216 782.875 19.99 0.01 0.00 134.64 170 4.903 117.837 170.09 -0.09 -0.03
8200K 25 9.012 731.893 25.00 0.00 0.00 122.1 175 4.805 110.927 175.08 -0.08 -0.03
6721.54 30 8.813 684.514 30.01 -0.01 0.00 110.95 180 4.709 104.426 180.07 -0.07 -0.02
5540.74 35 8.620 640.478 35.01 -0.01 0.00 100.94 185 4.615 98.261 185.10 -0.10 -0.04
4592 40 8.432 599.519 40.02 -0.02 -0.01 92.086 190 4.523 92.512 190.09 -0.09 -0.03
3825.3 45 8.249 561.392 45.02 -0.02 -0.01 84.214 195 4.433 87.136 195.05 -0.05 -0.02
3202.92 50 8.072 525.913 50.01 -0.01 -0.01 77.088 200 4.345 82.026 200.05 -0.05 -0.02
2693.7 55 7.899 492.790 55.02 -0.02 -0.01 70.717 205 4.259 77.237 205.02 -0.02 -0.01
2276.32 60 7.730 461.946 60.02 -0.02 -0.01 64.985 210 4.174 72.729 210.00 0.00 0.00
1931.92 65 7.566 433.157 65.02 -0.02 -0.01 59.819 215 4.091 68.484 214.97 0.03 0.01
1646.56 70 7.406 406.283 70.02 -0.02 -0.01 55.161 220 4.010 64.494 219.93 0.07 0.02
1409.58 75 7.251 381.243 75.01 -0.01 0.00 50.955 225 3.931 60.742 224.88 0.12 0.04
1211.14 80 7.099 357.808 80.00 0.00 0.00 47.142 230 3.853 57.207 229.82 0.18 0.06
1044.68 85 6.951 335.915 85.00 0.00 0.00 43.673 235 3.777 53.870 234.77 0.23 0.08
903.64 90 6.806 315.325 90.02 -0.02 -0.01 40.533 240 3.702 50.740 239.69 0.31 0.11
785.15 95 6.666 296.191 95.01 -0.01 0.00 37.671 245 3.629 47.788 244.62 0.38 0.13
684.37 100 6.528 278.253 100.00 0.00 0.00 35.055 250 3.557 45.001 249.54 0.46 0.16
598.44 105 6.394 261.447 105.00 0.00 0.00 32.677 255 3.487 42.387 254.44 0.56 0.19
524.96 110 6.263 245.705 110.00 0.00 0.00 30.496 260 3.418 39.917 259.34 0.66 0.23
461.91 115 6.135 230.952 115.00 0.00 0.00

12 | THERMISTOR TEMPERATURE DERIVATION | GEOKON
B.3 THERMISTOR RESISTANCE FOR 10KΩ
Thermistor Type: US Sensor 103JL1A
Resistance to Temperature Equation:
EQUATION 3: Thermistor Resistance for 10KΩ
Where:
T= Temperature in °C
LnR = Natural Log of Thermistor Resistance
A= 1.127670 x 10-3
B= 2.344442 x 10-4
C= 8.476921 x 10-8
D= 1.175122 x 10-11
Note: Coefficients optimized for a curve JThermistor over the temperature
range of 0 °C to +250 °C.
TABLE 9: Thermistor Resistance for 10KΩ
T= 1– 273.15
A+B(LnR)+C(LnR)3+D(LnR)5
Ohms Temp Ohms Temp Ohms Temp Ohms Temp Ohms Temp Ohms Temp Ohms Temp Ohms Temp
32,650 0 7,402 32 2,157 64 763.5 96 316.6 128 148.4 160 76.5 192 42.8 224
31,029 1 7,098 33 2,083 65 741.2 97 308.7 129 145.1 161 75.0 193 42.1 225
29,498 2 6,808 34 2,011 66 719.6 98 301.0 130 142.0 162 73.6 194 41.4 226
28,052 3 6,531 35 1,942 67 698.7 99 293.5 131 138.9 163 72.2 195 40.7 227
26,685 4 6,267 36 1,876 68 678.6 100 286.3 132 135.9 164 70.8 196 40.0 228
25,392 5 6,015 37 1,813 69 659.1 101 279.2 133 133.0 165 69.5 197 39.3 229
24,170 6 5,775 38 1,752 70 640.3 102 272.4 134 130.1 166 68.2 198 38.7 230
23,013 7 5,545 39 1,693 71 622.2 103 265.8 135 127.3 167 66.9 199 38.0 231
21,918 8 5,326 40 1,637 72 604.6 104 259.3 136 124.6 168 65.7 200 37.4 232
20,882 9 5,117 41 1,582 73 587.6 105 253.1 137 122.0 169 64.4 201 36.8 233
19,901 10 4,917 42 1,530 74 571.2 106 247.0 138 119.4 170 63.3 202 36.2 234
18,971 11 4,725 43 1,480 75 555.3 107 241.1 139 116.9 171 62.1 203 35.6 235
18,090 12 4,543 44 1,432 76 539.9 108 235.3 140 114.5 172 61.0 204 35.1 236
17,255 13 4,368 45 1,385 77 525.0 109 229.7 141 112.1 173 59.9 205 34.5 237
16,463 14 4,201 46 1,340 78 510.6 110 224.3 142 109.8 174 58.8 206 33.9 238
15,712 15 4,041 47 1,297 79 496.7 111 219.0 143 107.5 175 57.7 207 33.4 239
14,999 16 3,888 48 1,255 80 483.2 112 213.9 144 105.3 176 56.7 208 32.9 240
14,323 17 3,742 49 1,215 81 470.1 113 208.9 145 103.2 177 55.7 209 32.3 241
13,681 18 3,602 50 1,177 82 457.5 114 204.1 146 101.1 178 54.7 210 31.8 242
13,072 19 3,468 51 1,140 83 445.3 115 199.4 147 99.0 179 53.7 211 31.3 243
12,493 20 3,340 52 1,104 84 433.4 116 194.8 148 97.0 180 52.7 212 30.8 244
11,942 21 3,217 53 1,070 85 421.9 117 190.3 149 95.1 181 51.8 213 30.4 245
11,419 22 3,099 54 1,037 86 410.8 118 186.1 150 93.2 182 50.9 214 29.9 246
10,922 23 2,986 55 1,005 87 400.0 119 181.9 151 91.3 183 50.0 215 29.4 247
10,450 24 2,878 56 973.8 88 389.6 120 177.7 152 89.5 184 49.1 216 29.0 248
10,000 25 2,774 57 944.1 89 379.4 121 173.7 153 87.7 185 48.3 217 28.5 249
9,572 26 2,675 58 915.5 90 369.6 122 169.8 154 86.0 186 47.4 218 28.1 250
9,165 27 2,579 59 887.8 91 360.1 123 166.0 155 84.3 187 46.6 219
8,777 28 2,488 60 861.2 92 350.9 124 162.3 156 82.7 188 45.8 220
8,408 29 2,400 61 835.4 93 341.9 125 158.6 157 81.1 189 45.0 221
8,057 30 2,316 62 810.6 94 333.2 126 155.1 158 79.5 190 44.3 222
7,722 31 2,235 63 786.6 95 324.8 127 151.7 159 78.0 191 43.5 223