| 摘要 |
PURPOSE:To exactly detect a fault in an object by a ultrasonic wave and diagnose it, by providing a transmission electrode and a receiving electrode separately, making the transmitting circuit and the receiving circuit independent, and reducing a chasing phenomenon of the receiver. CONSTITUTION:The transmission electrodes 12a, 12a' are constituted on the surface of the ultrasonic wave piezoelectric vibrator 11 so as to be opposed to each other, and the receiving electrodes 13a, 13a' are constituted so as to be opposed to each other and also so as to meet at right angles with the electrodes 12a, 12a'. When the vibrator 11 is excited by applying AC voltage VS between the electrode 12a, 12a' from the transmitter 14, an ultrasonic wave is radiated into the medium. The ultrasonic wave which has been radiated into the medium hits against the reflecting body which is an inspection medium, is reflected, and it is transmitted to the vibrator as an echo. This echo passes through between the electrodes 13, 13a' when it is propagated inside of the vibrator 11. Therefore, since the vibrator 11 causes an elastic deformation, the bias current between the electrodes 13a, 13a' is varied. This variation is detected, and after it is amplified, the returned ultrasonic wave echo is reproduced by deteccting the wave. |
