Ferromagnetic material pulsed eddy current testing signal modeling by equivalent multiple-coil-coupling approach

A multiple-coil-coupling model is proposed for ferromagnetic material pulsed eddy current testing signals in this paper. The model uses circuit-theory-based analysis to replace the field-theory-based analysis in pulsed eddy current testing modeling. A non-linear trust-region algorithm is developed to fit the practical signal. The eigenvalue for thickness quantification is selected as one of the fitted parameters and the algorithm is developed and verified by actual measured data. The model is simple and suitable for engineering application.