If the display value of the anti-corrosion thermal resistance display instrument is lower than the actual value or the display value is unstable, then it may be that there is dirt in the protection tube, so the dirt can be mainly removed. But if the indication is negative, it may be the thermal resistance wiring error or thermal resistance short circuit, so as long as the wiring is corrected and the short circuit is handled, it can continue to be used. In addition to short-circuit and open-circuit problems, there are several common faults in the use of thermal resistance:The following analysis of four common failure phenomena and treatment 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: there are metal shavings, dust, dirt between the terminals and short circuit of thermal resistance in the protection tube; treatment method: remove metal shavings, clean up dust, water droplets, etc., find the short-circuit point to strengthen the insulation.2. Trouble phenomenon: the thermal resistance meter indicates infinity; possible causes: thermal resistance or lead wire short circuit or loose connection terminals, etc.; processing method: replace the resistor body or welding and tighten the connection screws.3. Trouble phenomenon: the display instrument indicates a negative value; possible cause: the display instrument and the thermal resistance are connected incorrectly or the thermal resistance has a short circuit; treatment method: correct the wiring, or find the short circuit, and strengthen the insulation.4. Failure phenomenon: The relationship between thermal resistance value and temperature has changed; possible cause: thermal resistance wire material is corroded and deteriorated; Treatment method: replace thermal resistance.Under normal circumstances, the resistance in the application process is relatively smooth, but sometimes there may be malfunctions, and the most common ones are open circuit and short circuit. The open circuit is usually caused by too thin thermal resistance wire. Let’s briefly understand how to deal with the short circuit and open circuit of thermal resistance.
Open circuit and short circuit are generally easy to determine, just a multimeter. That is, use the multimeter’s “×1Ω” file to measure, if the measured resistance is less than R0, it may be a short circuit; if the measurement indicates infinity, then it can be judged as open circuit. The short circuit is easier to handle, as long as it does not affect the length and thickness of the resistance wire, find the short circuit and dry it to strengthen the insulation. If it is an open circuit, the length of the resistance wire must be changed during processing, which will affect the resistance value. Therefore, only a new resistor body must be replaced, but welding repair is required. After welding, it must be verified before it can be used.
Post time: 21-09-21