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.