Remote field eddy current inspection of metallic tubes using GMR sensors

This article describes the inspection of metallic tubes using the remote field eddy current method. The excellent performance of giant magneto-resistance sensors in what concerns sensitivity, linearity, large bandwidth and direct assess to the magnetic field makes it a good choice for defect inspection in the applications where the measurement of low amplitude and low frequency magnetic fields is necessary. Experimental results with an artificial machined defect were included in the paper.