Simple Giant Magnetoresistance Probe Based Eddy Current System of Defect Characterization for Non-Destructive Testing

Abstract

The purpose of this paper is to present a new giant magnetoresistance (GMR) sensor, in eddy current testing technique for surface defect detection, in conducting materials, we show that the GMR based eddy currents probe is more sensitive than the inductive probe. A flat coil mounted on ferrite pot used to produce an alternate magnetic field, which gives rise to eddy currents in the material under test. Aluminum plates use with defects have nominal depths, widths, and lengths. The defects scanned with the sensing axis perpendicular to the defect length. Two parameters extracted from the GMR output voltage signal obtained, and a simple correlation between the defect’s dimensions and the GMR output voltage proposed.