| 摘要 |
PURPOSE:To enhance judging accuracy, by dividing a material to be checked into a plurality of sections, detecting the abnormal quality in every unit section, finding the difference in signal levels between the unit sections, integrating and averaging and averaging all the signals, and judging abnormality. CONSTITUTION:In order to detect the abnormal quality of the material to be checked 10, a current is conducted in an eddy current tester 1, and testing conditions are set so that sufficient detected signals can be obtained based on a reference material 11. The output signal from the tester 1 is imputted to A/D converters 13-1 and 13-2. In the case the abnormality of the material to be checked 10 is judged by the level difference between the unit sections along the longitudinal direction,said level difference is computed by a computing device 14-1 and supplied to a judging device 15-1. In the case judgement is performed for every one matrial, the digital value of the A/D converter 13-2 is imputted to an operating device 14-2, and the average value of the entire one material is judged by a judging device 15-2. In the case a plurality of the materials to be checked are compared and judged, the difference between the average value computed by the computing device 14-2, and the detected value for the preceding material to be checked is obtained by a computing device 14-3 and judgement is performed. |
