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脉冲叠加法脉冲叠加是一种广泛采用的干扰方法,用以确定超声脉冲渡越时间的微小变化,对单晶施加单向应力或流体静应力就产生这种变化。本文报道为一种自动脉冲叠加系统而研制的集成电路。与现有的这类设备相比较,它具有更高的稳定性和可靠性以及更低的成本。该系统可广泛用于高精密脉冲超声学,例如用来测定材料的三阶弹性常数。在主超声脉冲回波法中,在与平行平端面试样相连接的压电传感器上施加的基
Pulsed superposition Pulse superposition is a widely used method of interference that determines small changes in transit time of an ultrasonic pulse and produces this change when a unidirectional or hydrostatic stress is applied to the single crystal. This article reports an integrated circuit developed as an automatic pulse superposition system. Compared with the existing equipment of this kind, it has higher stability and reliability as well as lower cost. The system is widely used in high-precision pulsed ultrasound, for example to determine the third-order elastic constants of materials. In the main ultrasonic pulse echo method, the sample applied to the parallel flat-face piezoelectric sensor is applied to the base