Design and implementation of static calibration system for eddy current sensor

In the long-term use of eddy current sensors, there may be significant errors or even errors in the indicated values due to aging or the influence of objective environment. Therefore, it is necessary to regularly perform dynamic or static calibration of eddy current sensors based on their performance, timely discover and deal with the problems of eddy current sensors. In response to the demand of the metrology department to improve the static calibration efficiency of eddy current sensors, based on the application, characteristics, and working principle of eddy current sensors, the overall design of the automatic calibration device for static characteristics of eddy current sensors is completed using absolute calibration method. Stepping motors are selected as driving components, ball screws are used as transmission components, grating ranging is used as feedback, and 42CrMo is selected as the induction disk material to build the static calibration device for eddy current sensors. Finally, the calibration accuracy of the static calibration device for eddy current sensors was verified through experiments. The experimental results showed that the maximum control deviation of the static calibration device was within 5 microns, the measurement error was within 3 microns, and the voltage measurement accuracy reached 0.1%. The design of the static calibration device for eddy current sensors met the design requirements.