Magnetic Flux Leakage Measurement System for Nondestructive Testing of Water-Cooled Wall

A system that can calculate the abrasive corrosion and wall thinning of water-cooled wall tubes of boiler by measuring magnetic flux change was developed. A magnetizer, which is curved according to the cross-sectional shape of the tube, membrane and weld line, magnetizes a part of the water-cooled wall in the axial direction. At this time, the magnitude of the magnetic flux changes in a region where the thickness becomes thinner. This change in magnetic flux is measured by a magnetic sensor array deflected to one side from the center of the magnetizer.