| 摘要 |
PROBLEM TO BE SOLVED: To provide an inspection method capable of detecting surface flaw of a round bar even if it is a shallow flaw difficult to discriminate from noise.SOLUTION: In an inspection apparatus for surface flaw of a round bar, a flaw detection controller includes first determination means (step S22) and second determination means (steps S24 and S25). The first determination means determines that there is a flaw, when a height (Z) of flaw signals acquired by each probe is a first determination reference value (X) or more. The second determination means subjects the respective flaw signals to a preliminary determination for determining whether or not the height (Z) of the plurality of flaw signals acquired by the probes is equal to or more than a second determination reference value (Y) being lower than the first determination reference value (X) (step S24). When, by the preliminary determination, the plurality of flaw signals determined to be the second determination reference value (Y) or more are continuous at different positions from each other in the lengthwise direction of the round bar and the same position in the circumferential direction thereof (step S25), the second determination means determines that there is a flaw. |
