tekmar 084 Indoor Sensor - Manual (Page 3)

© 2007 D 084 - 05/07 3 of 4
Sensor Testing Instructions
A good quality test meter capable of measuring up to 5,000 k (1 k = 1000 ) is required to measure the sensor resistance. In addition
to this, the actual temperature must be measured with either a good quality digital thermometer, or if a thermometer is not available, a
second sensor can be placed alongside the one to be tested and the readings compared.
First measure the temperature using the thermometer and then measure the resistance of the sensor at the control. The wires from the
sensor must not be connected to the control while the test is performed. Using the chart below, estimate the temperature measured by
the sensor. The sensor and thermometer readings should be close. If the test meter reads a very high resistance, there may be a broken
wire, a poor wiring connection or a defective sensor. If the resistance is very low, the wiring may be shorted, there may be moisture in
the sensor or the sensor may be defective. To test for a defective sensor, measure the resistance directly at the sensor location with the
wires disconnected.
Note: Do not apply voltage to a sensor at any time as damage to the sensor may result.
Temperature Resistance
°F °C
-50 -46 490,813
-45 -43 405,710
-40 -40 336,606
-35 -37 280,279
-30 -34 234,196
-25 -32 196,358
-20 -29 165,180
-15 -26 139,402
-10 -23 118,018
-5 -21 100,221
0 -18 85,362
5 -15 72,918
10 -12 62,465
15 -9 53,658
Temperature Resistance
°F °C
20 -7 46,218
25 -4 39,913
30 -1 34,558
35 2 29,996
40 4 26,099
45 7 22,763
50 10 19,900
55 13 17,436
60 16 15,311
65 18 13,474
70 21 11,883
75 24 10,501
80 27 9,299
85 29 8,250
Temperature Resistance
°F °C
90 32 7,334
95 35 6,532
100 38 5,828
105 41 5,210
110 43 4,665
115 46 4,184
120 49 3,760
125 52 3,383
130 54 3,050
135 57 2,754
140 60 2,490
145 63 2,255
150 66 2,045
155 68 1,857
Temperature Resistance
°F °C
160 71 1,689
165 74 1,538
170 77 1,403
175 79 1,281
180 82 1,172
185 85 1,073
190 88 983
195 91 903
200 93 829
205 96 763
210 99 703
215 102 648
220 104 598
225 107 553