In order to accurately distinguish the cause of Hall Effect Sensor abrupt signal generation, a wavelet band analysis method based on mathematical model is proposed. For the measurement and control system in industrial process, the relationship between the frequency composition of the output mutation signal and the cause of the mutation is analyzed. Using wavelet band analysis technology, the high and low frequency signals are separated, and energy statistics are performed. According to the change of the energy ratio of high and low frequency signals, the cause of the mutation signal is judged. The computer simulation of the classic control system and the experimental results of the constant pressure water supply system show that the method can effectively diagnose whether the Magnetic Sensor is faulty.

In the measurement and control system, the output signal of the sensor is affected by many factors, and often abrupt changes. These mutation point values contain important fault information, accurately capture and distinguish the causes of these sudden changes, which is the key to Hall Effect IC fault diagnosis.

Generally, in industrial process control, the time constant of the controlled object is large and cannot respond to high frequency components in the abrupt signal. Based on the frequency band analysis technology of wavelet transform, the author explores the causes of sudden changes in Hall IC output signals, and provides a practical analysis method for fault diagnosis and performance evaluation of online sensors.