ULTRASONIC FLAW DETECTION FOR BAR- OR TUBE-LIKE MATERIAL TO BE INSPECTED

摘要

PURPOSE:To prevent damaging of a probe by stopping the rotation and the feed in its longitudinal direction of a material to be inspected when the initial minute vibrations of earthquake are sensed. CONSTITUTION:When a bar- or tube-like material 1 to be inspected is fed longitudinally while being rotated by a conveying mechanism 2 controlled by a controller 3, it is scanned by probes 5-7 disposed at prescribed intervals on the inner side of an annular body 4 in such a way that a locus of flaw detection assume a sprial shape. Defects are detected by a flaw detector 8. On the other hand, when a P-wave detector 9 detects the initial minute vibrations of earthquake, it outputs a sensing signal 10 to the controller 3 which in turn stops the rotation and conveying of the material to be inspected. Thereby, danger is made smaller despite the incoming of the major vibrations of earthquake, as compared to the case when the major vibrations are received while the material to be inspected is conveyed.