全自动相位差法声速测量实验数据的处理  

Automatic measurement of sound velocity by phase difference method and data processing method

作　　者：石明吉[1] 郭新峰[1] 李波波 王飞 SHI Ming-ji, GUO Xin-feng, LI Bo-bo, WANG Fei(School of Electronic and Electrical Engineering, Nanyang Institute of Technology, Nanyang 473004, Chin)

机构地区：[1]南阳理工学院电子与电气工程学院,河南南阳473004

出　　处：《物理实验》2018年第8期17-20,共4页Physics Experimentation

基　　金：南阳理工学院省示范校建设专项研究项目(No.SFX201718);南阳理工学院高等教育研究基金项目(No.2017-NGGJJJ-002);河南省重点科技公关项目(No.152102210217)

摘　　要：根据相位比较法声速测量数据的特点,采用数据处理手段将能量损耗的影响消除掉;为排除次峰的影响,考虑到声速测量数据中极值点的出现具有空间周期性,利用傅里叶变换处理数据得到待测信号的空间频谱图,确定了声波的波长并计算出声速.数据处理结果表明:由于消除了能量损耗的影响,排除了次峰干扰,使相位比较法测量声速的相对误差从0.97%减小为0.06%,也验证了次频共振现象是形成次峰的重要原因.According to the characteristics of the phase comparison method,a method of data processing was adopted to eliminate the influence of energy loss.Considering the spatial periodicity of the occurrence of extreme points in the sound speed measurement and the requirement to eliminate the influence of sub-maximum phenomenon,Fourier transform was used to process the data to get the spatial spectrum of the signal.The wavelength of the acoustic wave and calculate the sound speed were determined.The data processing results showed that the relative error could be reduced form 0.97%to 0.06% due to removing the sub-maximum interference by eliminating the influence of energy loss.In this case it was verified that the sub-frequency resonance phenomenon is a significant cause for the formation of sub-maximum phenomenon.

关 键 词：声速 相位比较法 傅里叶变换 次峰 次频 空间周期性 空间频率 

分 类 号：O422.1[理学—声学]