| 摘要 |
PURPOSE:To output a narrow-width, less ringing ultrasonic wave pulse and to measure precisely even at a short distance by providing plural electro-mechanical transducing elements for an ultrasonic wave pulse reflecting means, and radiating an acoustic wave. CONSTITUTION:A delay material 6 is interposed between piezoelectric elements 1 and 5 of an electro-mechanical transducing element. This delay material 6 makes outputs of the piezoelectric elements 1 and 5 opposite in phase. Electrodes 2 are provided on both surfaces of the piezoelectric elements 1 and 5 respectively. A protecting material 3 is provided on the electrode surface on an ultrasonic-wave radiation side and a packing material 4 is provided at the opposite side. Then, an impulse voltage is applied to the electrodes 2 and ultrasonic wave pulse are radiated from the piezoelectric elements 1 and 4 to an object as shown by an arrow. The acoustic wave pulse to the object is an intense single-shot pulse with narrow pulse width because the outputs of the piezoelectric elements 1 and 5 overlap each other and starting oscillations of the piezoelectric elements are given with priority while remaining oscillations cancel each other. Therefore the oscillations of the ultrasonic wave element become narrower in width and the ringing is reduced, so that a measurement is taken precisely even at a short distance. |
