全自动驻波法声速测量实验数据的处理方法研究  

Research on Processing Method of Experimental Data about a Fullautomatic Measurement of Sound Velocity by Standing Wave Method

作　　者：石明吉[1] 刘斌[1] Shi Mingji;Liu Bin(School of Electronic and Electrical Engineering,Nanyang Institute of Technology,Nanyang,Henan 47300)

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：《物理通报》2018年第12期97-101,共5页Physics Bulletin

基　　金：南阳理工学院省示范校建设专项研究项目"大学物理开放性实验教学方法与体系的研究与实践";项目编号:SFX201718;南阳理工学院高等教育研究基金项目"应用型本科高校公共实践教学平台运行机制研究";项目编号:2017-NGGJJJ-002

摘　　要：针对传统声速测量实验装置存在的缺陷,人们逐渐研制和使用自动化、智能化的新型声速测量装置.新型声速测量装置得到的测量结果数据量更大,包含的信息也更丰富.用传统的Origin软件线性拟合法处理数据误差较大,不能满足实验需要,有必要探索声速测量数据处理的新方法.新型声速测量装置的实验误差主要来自能量损耗和次频共振形成的次峰的影响.根据驻波法声速测量数据的特点和能量衰减的规律对数据进行修正,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,使驻波法测量声速的相对误差从1.66%减小为0.23%,比传统方法更适合于处理驻波法声速测量数据;此外,从另一个角度证明次频共振现象是形成次峰的重要原因.Aiming at short comings of traditional sound velocity measuring instrument, people proposed and used new automatic and intelligent sound velocity measuring instrument. The new measurement result has a greater amount of data and more information. To process the data by traditional Origin software linear fitting method will lead to large error, so it is necessary to explore a new method for data processing. The experimental error mainly comes from the influence of the energy loss and the sub-maximum of the sub-frequency resonance. The influence of energy loss can be eliminated by modifying the data according to the characteristics of data and energy loss. In order to eliminate the influence of sub-maximum phenomenon, considering the occurrence of extreme points in the sound speed measurement data has spatial periodicity, we use Fourier transform to process the data to get the spatial spectrum of the signal, determine the wavelength of the acoustic wave and calculate the sound speed. The data processing results show that Fourier transform eliminates the interference and reduces the relative error from 1.66% and to 0.23% , which is more suitable for processing the measurement data of sound velocity. From another point of view, the sub-frequency resonance phenomenon is an important reason for the formation of sub-maximum phenomenon.

关 键 词：声速测量仪 能量损耗 次峰 次频共振 傅里叶变换 空间周期性 空间频率 

分 类 号：O429[理学—声学]