| 摘要 |
PROBLEM TO BE SOLVED: To accurately determine the presence or absence of flaws at all times regardless of the occurrence of the eccentricity of materials to be inspected. SOLUTION: An eddy current flaw detection apparatus is provided with: a pair of exciting coils 2A and 2B arranged at an interval from each other in the longitudinal direction of a material to be inspected LM to be excited in antiphase; a plurality of magnetoresistive sensors 3 at radially symmetric positions in the circumference at intervals to the circumferential surface of the material to be inspected LM at intermediate positions between the exciting coils 2A and 2B to emit detection signals according to the intensity of detected magnetism; and a determination device for computing a sum of the detection signals of the magnetoresistive elements at the radially symmetric positions, acquiring sum signals, and determining the presence or absence of flaws in the circumferential surface of the material to be inspected LM on the basis of the sum signals. COPYRIGHT: (C)2009,JPO&INPIT
|
