APPLICATION OF A GIANT MAGNETORESISTIVE (GMR) SENSOR FOR CHARACTERIZATION OF CORROSION IN A LABORATORY SPECIMEN

摘要

This paper describes the use of a Giant Magnetoresistive (GMR) sensor to detect thickness variation in a multi-layered specimen. A series of frequency-response and modes-of-operation tests has been carried out to characterize a GMR sensor. Both the first and second harmonics of the GMR signal for corrosion detection were collected and analyzed. The experimental data showed that phase approach seemed to have better thickness discrimination over that of the magnitude approach.