| 摘要 |
PROBLEM TO BE SOLVED: To obtain a method and an apparatus in which a detection signal proportional to the size of a magnetic substance powder is fetched without being influenced by the position of the magnetic substance powder contained in an object, to be inspected, and by the twist of the object. SOLUTION: A wire 1 to be inspected is run, e.g. to the right direction from the left direction. A magnetic-field generation means 2 generates a magnetic field parallel to the running direction of the wire 1. A magnetic sensor 3 is surrounded by a magnetism cutoff container 6. The wire 1 is passed through the parallel magnetic field generated by the magnetic-field generation means 2, and it is then passed through a through hole which is opened in the magnetism cutoff container 6. When the wire 1 is passed through the parallel magnetic field, a magnetic substance powder 1a which is contained in the wire 1 is magnetized. When the magnetic substance powder 1a which is magnetized in parallel is passed through a part under the magnetic sensor 3, a pickup coil 3a inside the magnetic sensor 3 detects a change in the magnetic field, and the output of the magnetic sensor 3 is changed.
|
