©2017 MrPEX® Systems 519_D - 04/17
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Slab Sensor 5110079 Testing
A good quality test meter capable of measuring up to 5,000 kΩ (1 kΩ = 1000Ω) 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 room temperature using the thermometer. Disconnect the Sen and
Com wires from the thermostat. Using an electrical meter, measure the resistance
of the Sen and Com wires at the thermostat location. Using the temperature versus
resistance table, estimate the temperature measured by the sensor. The sensor
measurement 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. Once the test has
been completed, reconnect the Sen and Com wires to the thermostat.
Do not apply voltage to the temperature sensor terminals at any time as damage to
the sensor may result.
Temperature vs. Resistance Table
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
20
-7
46,218
Temperature
Resistance
°F
°C
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
90
32
7,334
95
35
6,532