PULSE EXCITATION TYPE INSPECTION DEVICE, AND PULSE EXCITATION TYPE INSPECTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a pulse excitation type flaw detection device that accurately detects flaws in an inspection target by transmitting a detection magnetic field deep into the inspection target.;SOLUTION: The pulse excitation type flaw detection device includes a probe having an excitation coil generating the magnetic field incident to the inspection target, and a detection coil for detecting a response magnetic field from the inspection target as an induction current or an induction voltage; and long pulse generating means that generates the incident magnetic field incident to the inspection target by the excitation coil by feeding a pulse current with a pulse width of 0.1 sec or more and 1 sec or less to the excitation coil. A long pulse magnetic field has a large quantity of low frequency component so that it efficiently transmits a skin material such as a heat insulation material, is less influenced by a skin effect of the inspection target, and reaches deep inside the inspection target. Consequently, in the inspection target, the response magnetic field is also generated in the deep portion of the inspection target and is detected by the detection coil of the probe. Thereby, the deep portion of the inspection target is also inspected accurately.;COPYRIGHT: (C)2012,JPO&INPIT