Interaction of a Current-Carrying Coil with a Slot in a Conducting Plate: A Problem of Eddy-Current Nondestructive Evaluation

Abstract

Eddy-current methods are often used in the nondestructive evaluation of conducting structures. In the simplest procedure, a current-carrying coil is scanned over the conducting workpiece, inducing eddy-currents into the structure. If there is a defect (which could be a crack, or some other conducting anomaly), then the driving-point impedance of the coil changes slightly. The variation of the change in impedance with position of the probe coil is, in some sense, a signature of the defect.