Thermocouple thermometer common fault for the indication of low value, or stop at zero. This is due to the thermocouple generated problems, may be poor contact or broken circuit, generally do not appear to indicate the phenomenon of high.
In order to ensure the measurement accuracy, the use of the cold end of the temperature compensation should be correct (commonly used compensation wire method), and pay attention to the thermal electrode and the earth between a good insulation.
RTD thermometer common fault: sometimes the pointer always points to the maximum. This is a resistance thermometer temperature measurement element break, so that the resistance of infinity, or poor contact between the two ends, contact resistance; another phenomenon is the pointer pointing to zero, or deflected to the negative direction. The reason is a short circuit in the temperature measuring element, resistance to zero, or due to the resistance thermometer protection casing leakage or icing caused by; there is another phenomenon is the pointer does not move, which is due to the bridge itself out of the problem, not working caused by.
In use to strictly prevent moisture into the RTD protection tube, after the display meter must not be open or short-circuit. In the inspection of the RTD, the measurement current should not be greater than 5mA.
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