FLAW-DETECTING SENSOR UNIT

摘要

PROBLEM TO BE SOLVED: To reduce wobbling noises attributed to chattering and vibration of an eddy current flaw detection sensor unit by burying O-ring shaped rubber fins into grooves provided on the outer circumference of a casing of the eddy current flaw detection sensor unit. SOLUTION: Detection coils 7 concurrently which serves for the generation of a magnetic field and the detection of an eddy current is wound on a groove formed in the circumferential direction of a cylindrical eddy current flaw detection sensor unit and the two coils are wound in directions opposite to each other to be connected to a bridge circuit within the eddy current flaw detection sensor unit. Rubber fins 6 are built in before and after a casing 5 of the sensor unit. The rubber fins 6 are made like an O-ring using a silicon based rubber material and securely fitted into a grove part on the outer circumference of the easing 5. When the eddy current flaw detection sensor is inserted into a specimen, the outer most circumference of the rubber fins 6 contacts the internal wall of the specimen. At this point, contact impact between the eddy current flaw detection sensor unit and the internal wall of the specimen can be eased by the rubber fins 6.