| 摘要 |
PURPOSE:To detect an obstacle precisely by an ultrasonic obstable penetration device in a nuclear reactor containment, by using a reflector which has small staircase-shaped reflecting surfaces differing in distance from an ultrasonic transmitter and reciever, and discriminating signals from the respective small reflecting surfaces. CONSTITUTION:An ultrasonic transducer 8 sends an ultrasonic wave in a direction specified by a transmitted-and-received-wave angle controller 10. A reflected wave from a reflecting element 11 enters the transducer 8 again and then enters an echo signal selection part 24 through an ultrasonic wave transmission and reception part. The reflecting surfaces of relfecting elements 11A-11C are each divided in a staircase shape and differ in distance from the transducer 8, so the received time of the reflected wave depends upon the reflecting surface. On the basis of the time S2 of reflection from a prescribed reflecting surface read out of a storage part 22 in accordance with an angle signal S0 from the controller 10, only a signal from the prescribed reflecting surface among reflected signals S32 is selected by a slection part 24 and the existence of an obstacle is detected by the presence of the signal. |
