MAGNETIC FLUX LEAKAGE DETECTING DEVICE FOR MAGNETIC BODY EMPLOYING MAGNETIC SENSOR AND MAGNETIC FLUX LEAKAGE DETECTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a magnetic flux leakage detecting device for a magnetic body, the characteristics of which are improved by using a TMR (tunneling magnetoresistance) sensor as a magnetic sensor, and a magnetic flux leakage detecting method.;SOLUTION: The magnetic flux leakage detecting device comprises: a magnetizer 21 which excites a magnetic body 30; a magnetic sensor module 20 having a magnetic line sensor 10 formed by arranging in the shape of a line a plurality of TMR magnetic sensors for detecting a leaked magnetic flux caused by inclusions, flaws, voids or the like in the magnetic body 30; and bias applying means for applying a bias magnetic field in a magneto-sensitive direction of the magnetic line sensor 10. The bias magnetic field is applied by the bias applying means in such a way that the sensitivity of the TMR magnetic sensor is in a high-sensitivity region, which is a linear region zone, beyond a low-sensitivity region in the vicinity of 0 oersted in the magneto-sensitive direction of the TMR magnetic sensor.;SELECTED DRAWING: Figure 12;COPYRIGHT: (C)2018,JPO&INPIT