| 摘要 |
PROBLEM TO BE SOLVED: To measure the depth of a tempered hard layer after it is confirmed whether a work is an untempered product even if the untempered product is mixed with a plurality of works to be measured. SOLUTION: Longitudinal ultrasonic waves are transmitted by a high frequency probe 2 while a focus F is set within a range from the position separated from the surface of the matrix W0 of a work W to the objective depth of a tempered hard layer and reflected waves are received by the probe 2. It the intensity of reflected waves is a threshold value or more even if surface reflected waves S are removed, scattered waves C are judged to be generated from the matrix W0 and the work is confirmed to be an untempered product. Thereafter, the depth of the tempered hard layer is measured. |
