The non-destructive evaluation (NDE) of metal surfaces can be accomplished using the alternating current field measurement (ACFM) technique [1]. In this technique a thin-skin eddy current is induced in the metal and the magnetic field above the metal surface is monitored for any perturbation caused by surface defects. In the non-uniform ACFM, the incident field may be produced by a coil or a wire loop carrying a high frequency current [2].