| 摘要 |
PROBLEM TO BE SOLVED: To provide a leakage flux flaw detecting method for stably discriminating a surface defect from an internal defect and performing detection regardless of measuring conditions. SOLUTION: Signal output from a magnetic sensor 4a and signal output from a magnetic sensor 4b are passed through a preprocessing device 9, amplified, and processed by filtering etc., and signals are branched into two. One is converted into a two-dimensional binarized image at a binarizing device 10. On the other, signals of the sensors each corresponding to the same location are compared and computed at a comparator 11, a defect is detected at a signal computing device 12 on the basis of the signals, and the location of the depth of the defect is simultaneously measured. A defect determining device 13 receives a signal from the signal computing device 12 in the plurality of leakage flux detecting parts arranged in the lateral direction and a signal from a pulse generator 14 coupled to a transfer roller 2b and finally determines the defect. COPYRIGHT: (C)2004,JPO
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