基于超声波近完全相消相干测量声速  

Measurement of sound speed based on nearlycomplete destructive interference of ultrasound

作　　者：闫志涛[1] 敬天慧 谭覃 许德飞 YAN Zhi-tao;JING Tian-hui;TAN Tan;XU De-fei(Department of Fundamental Courses,Institute of Disaster Prevention,Yanjiao,Hebei 065201,China)

机构地区：[1]防灾科技学院基础部,河北燕郊065201

出　　处：《大学物理》2022年第7期54-57,共4页College Physics

基　　金：防灾科技学院教研与教改项目(JY2021B32);中央高校基本科研业务费(ZY20180113)资助

摘　　要：本文搭建了一个超声波干涉装置,其中引入两个可独立调节的波源,一个为固定波源,另一个为可平行移动波源.利用该装置,可基于超声波近完全相消相干条件测定其波长,进而精确地测量声速.该方法是对现行大学物理实验课中声速测量方法的一个改进,同时该装置也可以演示频差较小的两列声波叠加产生的拍频现象.An ultrasonic interference device is built in this paper,in which two independent and adjustable wave sources are introduced.One is a fixed wave source and the other is a parallel moving one.With this device,the wavelength of ultrasonic waves can be measured based on nearly complete destructive interference of waves,and then the speed of sound can be measured accurately.This method can be regarded as an improvement in the measuring methods of sound speed in the current experimental course of college physics.And this device can also be used to demonstrate the phenomenon of beats caused by the superposition of two waves of slightly different frequencies.

关 键 词：相消相干 声速测量 拍频 

分 类 号：O422.1[理学—声学]