Study on defect type in eddy-current testing based on phase spectrum analysis

This article proposes the use of phase angle gradient as a feature to detect and classify different types of defects. Based on the principle of eddy-current testing (ECT), the ECT platform was designed and manufactured. Based on phase-sensitive demodulation principle, the phase angle and gradient of the detected signal are analysed. The results show that the phase angles and phase angle gradients of different types of defect detection signals show different trends; the phase angle gradient of the integrated position direction and frequency direction can effectively identify the defect type.