Statistical Test Method Used to Measure the Thickness Based on the Electromagnetism Way

In this paper, the statistical test method is used to process the single data. The data is vary huge in the measuring system, because the detecting speed of the measuring system is fast. So this method holds an important role in the platform. For each detecting point, the probe would detect for many times and obtain the data that stored in the computer. This statistical test method is used to select a suitable signal to the computing algorithm based on the distribution parameters skewness and kurtosis. So it costs a little time to search a well signal from the big data set. After selecting the data from the huge data set, the Fast Fourier Transform Algorithm (FFT) is used. By analyzing the frequency of the detecting signal, it could be used to measure the thickness, because the eddy current frequency spectrum have closing relationship with the thickness. For different thickness, the frequency spectrum is different and the frequency spectrum is wider when the thickness is thinner. The results could show that the proposed method could solved the problems of the huge data set and could improve the accuracy.