IMAGE PROCESSING OF DATA OBTAINED IN EDDYCURRENT NONDESTRUCTIVE EVALUATION OF METALLIC PLATES

A. Lopes Ribeiro, H. Geirinhas Ramos, D. Pasadas, T. Rocha

Abstract

This paper describes the usage of a planar excitation coil in a nondestructive testing experiment, using the eddy current method under sinusoidal excitation. After scanning a rectangular area on the metallic surface of the specimen under test, the probe signals obtained by a giant magneto-resistor sensor, were displayed in the form of a 2D representation. To determine the geometric form of the defects inside an aluminum plate, an inversion algorithm was tested. The algorithm is based on a kernel method. It uses the Discrete Fourier Transform (DFT) and Tikhonov regularization to obtain the spatial distribution of currents inside the aluminum plate.

Keywords

non-destructive evaluation, eddy-currents, ill-posed problems, Tikhonov regularization

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IMEKO-WC-2012-TC4-O17.pdf

DOI

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IMEKO TC

TC4 - Measurement of Electrical Quantities

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