PHASED SCAN EDDY CURRENT ARRAY PROBE AND A PHASED SCANNING METHOD WHICH PROVIDE COMPLETE AND CONTINUOUS COVERAGE OF A TEST SURFACE WITHOUT MECHANICAL SCANNING

摘要

A phased scanning method and phased scan eddy current array probe suitable for in-situ eddy current inspection of a structure without mechanical scanning. Overlapping subsets of the sensor elements within the array probe are dynamically connected in series and sequentially scanned to simulate the mechanical motion of a conventional array probe along a test surface. An algorithm to effectively balance the scan data is provided which comprises obtaining a reference scan at the time of probe installation, storing the measurement data from this reference scan in a memory device located within the probe, subtracting this reference curve from the curve obtained by all subsequent measurement scans to produce an adjusted curve, and processing the resulting adjusted curve through a high pass filter. A technique for verifying sensor elements of an eddy current array probe after permanent or semi-permanent installation against a test structure is also provided.