Wall thickness detection of stainless steel based on pulse eddy current late signal slope

The pulsed eddy current signal of 304 stainless steel was analyzed, and the slope of the late signal in the single logarithmic coordinate system was used as the characteristic value to characterize the wall thickness.The relationship between the late signal slope and the stainless steel wall thickness is fitted. The effects of lift off height and defect shape on the signal are analyzed through experiments.This method has been applied in practice with good effect.