Monotonicity principle in pulsed eddy current testing and its application to defect sizing

This article applies monotonicity principle to time constants in pulsed eddy current testing. This principle allows for a non-iterative imaging method for defects in conducting materials. The source free response in pulsed eddy current testing consists of linear combination of exponential decaying waveforms. A major challenge of this method is to accurately estimate the time constants from measurement of such responses. Preliminary results of estimating dominant time constants are presented. Potentially, this information can be used to predict the size of a volumetric defect regardless of its location, i.e. this method is robust in the case of both surface and buried defects.