A TRANSFER-FUNCTION METHOD FOR EDDY-CURRENT NONDESTRUCTIVE TESTING

A transfer function method is introduced to the eddy current nondestru ctive testing (ECT) in this paper. Actually ECT is to investigate the differences of the materials with and without flaws. The transfer func tion of the tested materials for ECT is defined as the frequency prope rty of the materials. With the transfer function method, the differenc e is an area bounded by the two transfer functions of the materials wi th and without flaws, while the impedance method can only provide a fe w discrete impedance values. Obviously, the area can provide more info rmation of the materials than a few discrete values. The numerical and the experimental studies have proved that the transfer function metho d is an efficient approach for ECT.