| 摘要 |
PURPOSE:To improve an S/N, by multiplying outputs of two probes which are positioned facing and opposite to each other at a distance object to be measured and simultaneously scan it from a reverse direction to each other. CONSTITUTION:The gate position of a flaw detector is set so that an echo in the proximity of an inner surface of an object to be measured is monitored, and two probes 4 and 4' are caused to scan in an axial direction simultaneously. In the case of a detective echo, an analogue signal of each of detectors 8 and 9 simultaneously appears by means of the probes 4 and 4', and an output wave form of a multiplier 10 appears in a wide manner. In the case of a flase echo, after a taper part 6 is defected by a probe I4, a taper part 7 is defected by a probe II4', and a difference DELTAY in a detecting position is produced between the two and on a scanning graph. The multiplier 10 multiplies the output of the two probes at corresponding points according to scanning of the probes I4 and I4', and the outputs almost disappear. |
