Common faults and treatment methods of thermal resistance

The common thermal resistance is the most commonly used temperature detector in the middle and low temperature area. It is not only widely used in industrial measurement, but also made into a standard reference thermometer.

The following analyzes four common fault phenomena and processing methods:
1. Failure phenomenon: the indicated value of the displayed thermal resistance is lower than the actual value or the indicated value is unstable;
Possible reasons: metal chips, dust, dirt between the terminals and thermal resistance short circuit in the protection tube;
Treatment method: remove metal shavings, clean dust, water drops, etc., find short-circuit points to strengthen insulation.
2. Failure phenomenon: the thermal resistance meter indicates infinity;
Possible reasons: thermal resistance or short circuit of the lead wire or loosening of the terminal, etc.;
Treatment method: replace the resistor or weld and tighten the wiring screws.
3. Failure phenomenon: display instrument indicating negative value;
Possible reason: display the wrong connection between the instrument and the thermal resistance or the thermal resistance is short-circuited;
Treatment method: Correct the wiring, or find the short circuit, and strengthen the insulation.
4. Failure phenomenon: the relationship between the thermal resistance value and the temperature changes;
Possible cause: The material of the thermal resistance wire is corroded and deteriorated;
Treatment method: replace the thermal resistance.