| 摘要 |
PURPOSE:To detect various disorders and to enhance the reliability of each function by converging the ultrasonic beams of a plurality of vibrators to enhance sensitivity and using a reduced number of the vibrators less than the number of ones used at the time of flaw detection to perform the transmission and reception of an ultrasonic wave. CONSTITUTION:At the time of flaw detection, when vibrators 3a - 3c are selected by a transmission and reception selecting circuit 11 to be simultaneously driven, this state becomes same to such a state that a vibrator having an area three times equiva lently is driven and a narrow beam ultrasonic wave 4A is generated. When adjacent vibrators are selected like 3b - 3d' 3c - 3e by the circuit 11 and successively shifted at every definite time interval, the flaw detection of a material 1 to be inspected can be uniformly performed with high sensitivity by narrow beam ultrasonic waves 4A - 4D generated from respective vibrator groups. Next, when a reduced number of vibrators less than the number of ones used at the time of flaw detection, for example, only the vibrators 3b' 3e are driven at a time separate from flaw detection, ultrasonic beams 4b' 4e become wide in beam directional angle and, therefore, a stable surface reflected echo or bottom surface reflected echo is obtained. Therefore, the check of an acoustic coupling state or the tracking of a flaw detection gate position becomes possible. |
