A Semi-Analytical Method for Modelling of EC Probes for Detection of Thin Defects in Metals

In this paper, a novel, simplified semi-analytical approach for modelling and performance study of Eddy-Current (EC) probes has been proposed for detecting thin defects in nonmagnetic, metallic objects. The proposed technique is based on the volume integral form of Biot-Savart law. The expression of the net magnetic field, at a suitable point in the probe, is evaluated. Thus, the methodology is suitable for integrated magnetic sensor-based EC-probes. The semi-analytical method is applied to two different probe configurations, and their responses are derived. The performance of the proposed technique is comparable to simulation results from commercial finite-element-based software and experimental results obtained using hardware prototypes of the EC probes. Thus, this paper provides a simple mathematical approach for analyzing EC-based defect detection problems.