Determining Conductivity and Thickness of Continuously Varying Layers on Metals Using Eddy Currents

Electrical Resistivity Reconstruction of Graphite Moderator Bricks From Multi-Frequency Measurements and Artificial Neural Networks

“…To overcome this limitation, multi-frequency (MF) excitation can be applied to excite the EC sensor. In this way full spectral information about the material of interest can be obtained [7]- [12]. In this context, with the application of the MF excitation technique, it is possible to probe the graphite fuel channel brick to different depths and collect…”

“…In this work the authors proposed a method based on MF EC measurements and steepest descent algorithm to reconstruct the conductivity distributions and thickness of layered structure independently. Related work describing a method for estimating the thickness and conductivity of layer conductors by comparing the measured data with Dodd and Deeds [16] theoretical solution was presented by Moulder et al [11] and Uzal et al [12]. Yin et al [13], [14], [15] proposed analytical solution for solving forward problem for air cored coil placed above layered conductor and employed a modified Newton Rapson method to reconstruct both smoothly varying and step changing electrical conductivity and magnetic permeability profiles of a sample as a function of depth.…”