Series expansions in eddy current nondestructive evaluation models

The well-established Dodd and Deeds models, that are widely used in eddy current nondestructive evaluation (NDE) and have served the industry for three decades, are being reformulated. Integral expressions for the electromagnetic field and the impedance of the eddy current coil are replaced by series expansions. As a result, computation time is considerably reduced, convergence is better controlled and computer implementation is greatly simplified. The analysis is performed for a coil over a conducting half-space and a coil inside a borehole with a conducting wall.