Transmitters
120
Checking the coolant temperature transmitter by measuring the resistance
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0 102030405060708090100110120
_C
Ω
1
2
Dip temperature sensor up to the lower edge of the hex section into a mixture of water and 30 % anti–
freeze/anti–corrosion agent. The liquid must be circulated during this measurement. Check the temperature
with a thermometer as the liquid is heated. Measure the resistance and compare it with the calibrated
curves (_F = 1.8_C + 32).
Curve 1: Temperature transmitter for 1 electrical instrument
Curve 2: Temperature transmitter for 2 electrical instruments
Temperature transmitter for 1 electrical instrument: checking values and tolerance of transmitter resistance
Temperature _C 40 60 90 100
Resistance Ω 296.0 134.0 51.2 38.5
Tolerance – ± 13.5 Ω = ± 4_C ± 4.3 Ω = ± 3_C ± 3.0 Ω = ± 3_C
Temperature transmitter for 2 electrical instruments: checking values and tolerance of transmitter
resistance
Temperature _C 60 90 100
Resistance Ω 67 25.60 19.25
Tolerance ± 6.5 Ω = ± 4_C ± 2.1 Ω = ± 3_C ± 1.5 Ω = ± 3_C