声管中双水听器法估算反射系数产生的几个误差及降低方法

Study on Operating Life of Quartz Oscillating Type Pressure Sensor

通过对组装式石英谐振压力传感器解剖,分析影响传感器工作寿命的主要因素,并对其深入探讨,提出改善传感器工作寿命的具体措施。

a hydroacoustic tube designed for measuring a coefficient of sound reflection from various materials and constructions by a two-hydrophone technique is examined. It is shown that the specific, unstudied before, vibrational interferences essentially affecting the measurement accuracy may arise in such devices. It is ascertained that the reason of their occurrence is a mechanical contact between the sound source and the walls of the tube through its structure elements.On the basis of offered calculation scheme the relative noise level and coefficient of sound reflection from thin air layer were numerically estimated. It is shown that for some frequencies the determining of reflection coefficient might become practically impossible. The two ways of noise level reduction are proposed. One of them consists in rational choice of tube structure elements, while the second one is based on special processing of the signal received from vibrosensors and hydrophones placed inside the tube.