Research on Coating Thickness Measurement with Eddy Current

The thickness of the surface coating has a great influence on their performance in the application of metal materials. Accurate measurement of the coating thickness is of great significance. In this paper, based on the eddy current thickness measurement principle, the information of coating thickness can be converted into the parallel resonance impedance as a reaction of the information using the digital conversion function of LDC1000 chip. The reasonable probe structure is designed, and the data processing methods such as mean filtering, weighted filtering and zero point calibration are adopted to ensure the accuracy and stability of the measurement. In the comparison of the RP-Thickness curve obtained from the fitting of the experimental data by the least weighted square method and the simulation curve of RP and thickness, the results show that the two curve are basically consistent, which proves the reliability of the proposed scheme. Compared with the previous methods, this scheme can reduce the cost of measurement and guarantee the accuracy and stability.