利用DSO的REF功能测量超声波速度

摘要

Measuring ultrasonic velocity plays a vital role in ranging and localization,liquid flow-rate measurement,elastic modulus measurement,transient gas temperature change measurement and other applications.A straightforward sound velocity measuring method which is based on delay time in receiving signal is presented in this paper,and measuring delay time is presented by fully using noise reduction treatments of digital storage oscilloscope on signal and taking advantage of REF function of digital storage oscilloscope to achieve integral calibration.The experiment testifies that measurements are fairly accurate and a new thread of thought is provided for accurate sound velocity measurement.This method can be applied in the basic college physics experiment or the demonstration teaching in classroom,which enables students to intuitively understand the principle and process of sound velocity measurement,and has certain references to inspire students' flexible and full use of the function of instruments.%超声波传播速度的测量,在测距与定位、液体流速测定、弹性模量测量、气体温度瞬间变化测量等方面的应用中十分重要.文中给出一种基于接收信号延迟时间的较直观的声速测量方法,其中延迟时间的测量是充分利用了数字存储示波器对信号的多种降噪处理方法,并且利用了数字存储示波器的参考波形(REF)功能对接收信号进行整体对准实现的.实验证明这种方法的测量结果相当准确,为声速的精密测量提供了一种新的思路.这种方法可应用在大学基础物理实验或课堂演示教学环节,可使学生对声速测量的原理和过程有更加直观的认识.对启发学生灵活使用及充分发挥仪器的功能都有一定的借鉴作用.