DETECTING DEVICE FOR FINE POWDER OF MAGNETIC SUBSTANCE

摘要

PROBLEM TO BE SOLVED: To continually detect fine, foreign magnetic substances contained in a long-size subject for inspection which travels continuously, without damaging the subject for inspection. SOLUTION: This device includes a magnetic field generation means 2 for magnetizing a subject 1 for inspection in a specific direction and a magnetic sensor 3 which detects fluctuation of the magnetic field in a specific area containing the subject 1 for inspection which is magnetized by the magnetic field generation means 2. The magnetic field generation means 2 magnetizes the subject 1 for inspection by producing the magnetic field that is perpendicular to the direction of travel of the subject 1 for inspection. The magnetic sensor 3 is placed so that it can detect with high sensitivity the magnetic field oriented in the same direction as the magnetic field generated.