Study on the Sensitivity of Sweep Frequency Eddy Current Probes Using Finite Element Simulation

Sweep frequency eddy current testing (SFECT) is a nondestructive testing (NDT) method that relies on frequency dependent impedance of coil at resonance and used for investigating change in electrical conductivity of nonferromagnetic electrically conducting materials. The sensitivity of the technique depends on the optimal parameters of probe coil. The geometrical and fabrication parameters of the probe are studied in detail through finite element (FE) modeling study to understand its influence on sensitivity of probe. From this modeling study, the influential probe parameters are identified. The validation of the model prediction is carried through the experiments using similar fabricated probes. The results demonstrated the excellent correspondence between the model prediction and experimental observations on peak frequency (PF) and its sensitivity. The study provides an approach for enhancing the sensitivity of an SFEC probe by identifying the fabrication parameters having significant influences on the PF of the coils.