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© 203 Watts Radiant
Floor Sensor 079 Testing
A good quality test meter capable of measuring up to 5,000 kΩ ( kΩ = 000Ω) 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 floor temperature using the thermometer. Disconnect the S and
Com wires from the thermostat. Using an electrical meter, measure the resistance
of the S 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 S and Com wires to the thermostat.
Temperature vs. Resistance Table
Temperature
Resistance
°F
°C
-50
-46
490,83
-45
-43
405,70
-40
-40
336,606
-35
-37
280,279
-30
-34
234,96
-25
-32
96,358
-20
-29
65,80
-5
-26
39,402
-0
-23
8,08
-5
-2
00,22
0
-8
85,362
5
-5
72,98
0
-2
62,465
5
-9
53,658
20
-7
46,28
25
-4
39,93
30
-
34,558
Temperature
Resistance
°F
°C
35
2
29,996
40
4
26,099
45
7
22,763
50
0
9,900
55
3
7,436
60
6
5,3
65
8
3,474
70
2
,883
75
24
0,50
80
27
9,299
85
29
8,250
90
32
7,334
95
35
6,532
00
38
5,828
05
4
5,20
0
43
4,665
5
46
4,84
Do not apply voltage to a sensor at any time as damage to the sensor may result.
