Fault Diagnosis and Prediction of PH Sensor

In this paper, in accordance with the study of pH sensor characteristic, the fault type and formation of pH sensor on line are analyzed and the new method of fault diagnosis is proposed based on the time series. The theory of the time series prediction is applied in the automation operation sewage disposal system of pH sensor, caused the failure diagnosis from qualitative analysis to quantitative expression, and digitalized discrimination is realized in fault type identification of the pH sensor. The application results of the method in the sewage disposal system show that correct rate of fault diagnosis of pH sensor increases from 60%-70% to 90% the difficult problem that is caused by the relation of fault in control system is successfully solved, and it provides a new way for prediction of sensor fault diagnosis in other control system.