| 摘要 |
PURPOSE:To inspect spot welding with high efficiency by calculating the plate thickness of a welded part from the receiving time difference of two continuous echoes among respective received echoes and the preliminarily measured sonic velocity of the welded part. CONSTITUTION:When a constant ratio for forming comparing lines LU, LD and a gate range are inputted to a control part 19 from an input part 18, the control part 19 forms the comparing lines LU, LD to store the same in a memory part 16 and displays the compared reference line and comparing line LU and the acceptance area surrounded by the gate range on a display part 17. Next, control part 19 receives the respective echoes from a welded part to be inspected and calculates the plate thickness of a welded part from the receiving time difference between two continuous echoes among the respective received echoes and the preliminarily measured sonic velocity of the welded part and selects only the echo present with the predetermined tolerant range of the calculated plate thickness and present with a predetermined time after an ultrasonic wave is oscillated among the respective received echoes as an object judging acceptance or rejection and the welded part is judged to be acceptable when the max. amplitude value of the selected echo is under the upper limit comparing line. |
