Impact of selected parameters on eddy current attenuation in conductive materials

The paper addresses attenuation of eddy currents in conductive materials under non-destructive inspection. Impact of selected parameters of an exciting system on the attenuation is studied by numerical means. Simple circular coil is utilized to drive eddy currents in a conductive plate. The coil is driven with the harmonic current under several frequencies, respectively. Outer diameter of the coil is varied together with the clearance between the coil and the plate surface. Distribution of the eddy current density in the plate is studied and the results are analyzed in absolute values and the normalized ones as well. It is demonstrated that the coils' dimensions as well as its position over the plate surface play significant role in attenuation of eddy currents in a case when the plate thickness is comparable to the standard penetration depth.