Automated Algorithms for Eddy Current Array Probes for Steam Generator Inspection

Abstract

Eddy current array probes have recently been introduced for the inspection of steam generator tubes. Efficient analysis of the acquired data requires automated algorithms. We describe the Automated Nondestructive Testing Array Evaluation System, a software tool for detecting and characterizing degradation of steam generator tubing from array probe data. Defect detection is based on the sequential probability ratio test and image processing algorithms. The maximum depth of each defect is determined by using nonlinear regression, the estimated amplitude and phase at selected frequencies, and a set of heuristic rules.