IMPROVEMENT OF MAGNETIC INTERFACE COUPLING THROUGH A MAGNETIC COUPLING GEL

Surface measurement of magnetic properties is potentially a very advan tageous technique for nondestructive evaluation. The effect of a magne tic coupling gel on surface magnetic measurement, is reported in this paper. Test results under three interface conditions are presented and compared. It was found that the magnetic gel reduces the variability of the measurement by improving the magnetic interface coupling betwee n the sensor and test specimen. A simple model of a magnetic circuit i s analyzed to show the coupling function of magnetic gel. From these r esults, it is deduced that the magnetic coupling gel plays an importan t part in improving reliability of the magnetic measurements.