MAGNETISM INSPECTION METHOD AND ITS DEVICE

PROBLEM TO BE SOLVED: To easily inspect a changing degree to a magnetic condition from a nonmagnetic condition by arranging a magnet means at an interval from an inspection object, and detecting a part of a magnetic flux of not passing through the inspection object among a magnetic flux reaching an S pole from an N pole. SOLUTION: When an inspection device 10 is arranged so that a contact surface 32 of a spacer 14 comes into contact with an outside surface of an inspection object 30, in the case where the inspection object 30 is a nonmagnetic material, a magnetic flux of a permanent magnet 20 passes through passages 40 and 42. A part of a magnetic flux 40 reaching an S pole 28 from an N pole 26 to constitute the same magnetic circuit on the inspection object 30 side, passes through a Hall element 34 of a magnetic detector 16. A part of the magnetic flux 40 is detected by the magnetic detector 16, and density of the magnetic flux passing through the Hall element 34 is found on the basis of an output signal of the magnetic detector 16, and is visibly displayed. Since this magnetic flux density changes by depending on a change (a change to a magnetic condition from a nonmagnetic condition) in magnetic permeability of the inspection object 30, magnetic permeability of the inspection object 30 and a changing degree to a magnetic condition from a nonmagnetic condition, can be detected from the obtained magnetic flux density.