An improved ferromagnetic material pulsed eddy current testing signal processing method based on numerical cumulative integration

A pulsed eddy current (PEC) testing signal processing method for ferromagnetic material is presented. Without any filtering process that may produce signal distortion, the numerical cumulative integration of the noisy PEC signal is calculated and subsequently fitted to the theoretical model. The model parameter estimation is later applied to quantify the specimen thickness and reconstruct a denoised PEC signal. A comparison is made between the presented method and the former direct-fitting method. The results demonstrate that the presented method improves the testing performance in terms of the detectable thickness range, the probe lift-off distance, and the measuring time.