GMR-based instrument for ECT on conductive planar specimens

The paper proposes a novel instrument for the eddy current non-destructive testing on conductive materials. The instrument is composed by a smart eddy current probe, based on a Giant Magneto Resistance sensor, and a suitable processing unit. Key features of the proposed instrument are the capability to detect, locate and characterize thin defects as superficial and sub-superficial cracks. The cost effective of the proposal, and the metrological performances of the realized instrument make it suited in several applications fields such as aerospace and maritime. In the paper the steps followed toward the instrument realization are described together with a preliminary experimental characterization.