探头固定特性对非介入式压力检测性能的影响

Effect of the Fixed Characteristics of Probe on the Detection Performance in the Non-Intrusive Pressure Measurement

基于超声波的非介入式压力检测是利用超声波在容器壁中的传播时延与容器内压有关这一特性来实现压力检测。获得高信噪比的超声波信号和精确的传播时延是提高压力测量精度的关键。本文采用一发两收(一个发射探头、两个接收探头)模式,研究了接收探头固定特性对超声波信号幅值以及传播时延的影响。实验结果表明,随着探头荷载的增加,超声波信号幅值会随之增大并趋于稳定。此外,改变两个接收探头的荷载大小,超声波传播时延也会随之而变化,而且其传播时延改变量和由压力容器内压所引起的传播时延处于同一数量级。因此,在实际应用中应确保两个接收探头固定特性一致,从而提高压力测量精度。

The ultrasonic approach for non-intrusive pressure measurement aims to achieve the pressure measure-ment utilizing the relationship between the travel-time change in the vessel wall and the pressure. The key of im-proving the accuracy of pressure measurement is to obtain the ultrasonic signal with high signal- to- noise ratio（SNR）and the precise travel-time change. In this paper,the dual-receivers（one transmitter probe and two receiv-ing probes）mode was used and the effect of the fixed characteristics of receiving probes on the ultrasonic signal am-plitude and the travel-time change wasinvestigated. Experimental results show that the amplitude of received ultra-sonic signal will increase with the increase of the probe loadand stay at a stable level when the load increases to acertain extent. Besides,the travel-time change of the ultrasonic wave will be influenced by the fixed load variation.The travel-time change caused by the fixed characteristics and the travel-time changeinduced by the pressure are inthe same order of magnitude. Therefore,in practical application,it is necessary to ensure the fixed characteristics ofthe two receiving probes consistent,which can improve the accuracy of the pressure measurement.