Temperature instrumentation failure is usually manifested as a high, low, or slow response, when the temperature instrumentation failure, pay attention to the following two points:
First, most of the temperature instrumentation using electric instruments;
Second, the system instrumentation has a relatively obvious hysteresis in the detection.
(1) Temperature instrument data suddenly change to the highest or lowest, usually belonging to the instrumentation system aspects of the problem, this is due to the instrumentation system itself having a certain hysteresis, rarely appearing sudden changes. If sudden changes occur, they are usually caused by abnormalities in the RTD, thermocouple, or transmission amplifier.
(2) When high-frequency abnormal fluctuations occur in the temperature control instrument, it is usually due to improper setting of PID parameters.
(3) When the temperature control instrumentation has a relatively obvious slow fluctuation, it is generally caused by changes in the process operation.
If the influence of the process operation can be excluded, then it is most likely that the instrument control system is malfunctioning.