DEFECT DETECTION DEVICE USING LEAKAGE FLUX METHOD OF A STEEL PIPE COATED WITH PAINT, AND AN OPERATION METHOD THEREOF

摘要

PURPOSE: A defect detection device and an operation method thereof are provided to detect defects by using leakage flux method of a steel pipe which is coated with paint.;CONSTITUTION: A defect detection device includes two permanent magnets (100,110) and a magnetic sensor (120). The permanent magnets move on the surface of a steel pipe, generate a magnetic leakage flux signal on a defective area which is exist on the steel pipe, and have different magnetic properties from each other. The magnetic sensor is positioned in between two permanent magnets, and detects magnetic leakage flux signals which are generated at different heights from each other by using a first magnetic sensor (122) and a second magnetic sensor (124) which have different heights from each other.;COPYRIGHT KIPO 2013;[Reference numerals] (100, 110) Permanent magnet; (120) Magnetic sensor; (122) First magnetic sensor; (125) Second magnetic sensor; (AA,BB) Moving; (CC) Steel pipe; (DD) Defect