| 摘要 |
PURPOSE:To measure the distance between a probe and an object to be inspected and detect an internal defect of the object by counting the number of times of skipping from the time position of an initially set gate to the position of a skipped gate. CONSTITUTION:A counter memory 19 provided to a computer device 20 is put in adding operation every time a trigger pulse is outputted, so the counting operation is carried out from the time position of the initially set gate to the gate position after skipping. Therefore, the counted value corresponds to the distance from the initially set gate position when the level of a reflection echo in the skipped gate exceeds the threshold level of a comparator 10 every time a controller 16 provided to an ultrasonic flaw detector 17 receives a trigger pulse. This counted value is processed to easily find the appearance position of the reflection echo in the gate at the skip position and a reflection echo such as a surface reflected wave, etc., from the object 1 is received to detect the distance between a probe 2 and the object 1. |
