Parameter measurement method is a practical and new method for fault diagnosis of hydraulic system. It combines with logic analysis method and greatly improves the speed and accuracy of fault diagnosis. First of all, the measurement is quantitative, which avoids the blindness and empiricism of individual diagnosis. Secondly, the fault diagnosis speed is fast. After several seconds to several seconds, the accurate parameters of the system can be measured, and then the diagnosis results can be obtained after simple analysis and judgment by maintenance personnel. Furthermore, compared with the traditional fault diagnosis method, this method can reduce the system load.

This fault diagnosis detection loop has the following functions:

(1)It can directly measure and directly display the flow rate, pressure and temperature of liquid flow, and indirectly measure the speed of pump and motor.

(2) The overflow valve can be used to simulate the loading of the tested part of the system, which is convenient and accurate for pressure adjustment. In order to ensure the accuracy of the measured flow, it can be directly observed from the thermometer testing temperature difference.

(3) It is suitable for any hydraulic system, and some system parameters can be tested without stopping.

(4)It has light and simple structure, reliable work, low cost and simple operation.

This testing loop combines the loading device and simple testing instrument together, which can be made into a portable testing instrument. It lays a foundation for the automation of detection, prediction and fault diagnosis.