Abstract
This paper discusses a feasibility of magnetic flux leakage (MFL) method for estimation of wall thinning on tube in nuclear power plant. A single magnetic yoke is fixed on the specimen, and then a magnetic field sensor scans the leakage field between the yoke legs. The single magnetic yoke with gauss meter fixed at the center of the yoke is also scanned over specimens having a slit. From both FEM analysis and experimental measurement, it is clarified that estimation of the size of slit fabricated in the specimen using profile of leakage field is possible; this indicates monitoring conditions of wall thinning will be possible by MFL method.