针对声学法测温中普遍存在的混响问题,提出一种基于波峰辨识的抗反射波干扰的声波传播时间测量法。在此基础上,设计了一套声波传播时间测量系统。系统以LabVIEW为软件平台.采用了LabVIEW与MATLAB混合编程技术。以扬声器、传声器、前置放大器、功率放大电路、扬声器选通电路、信号调理器、数据采集模块和带声卡的计算机构成硬件系统。实现了声波信号的产生、发射和接收、采集和传播时间计算的全过程。测试结果表明:文中算法在强反射波干扰下,仍可获得稳定的声波传播时间测量值。在系统中嵌入适当的温度场重建算法,可实现非接触的温度场监测。
Aiming at reverberation phenomenon ubiquitous in acoustic temperature measurement, an anti-echo interference measurement method for acoustic travel-time was proposed based on peak recognition.An acoustic travel-time measurement system was designed and developed. LabVIEW was used as the software design platform. Mixed programming with LabVIEW and MATLAB was used.The hardware system was composed of speakers, microphones, preamplifiers, power amplifier circuit, speaker gating circuit, signal conditioner, data acquisition module and personal computer with a sound card.The whole process of sound generating, transmitting and receiving, data acquiring and travel-time calculating were realized automatically.Test results show that the measurement values of acoustic travel-time acquired by the proposed method are stable even in strong reflection interference. As a result, non-contact temperature field monitoring can be realized by embedding proper temperature reconstruction algorithms into the system.