Matlab软件和逐差法在共振法和相位法测量超声声速中的应用

The Application of Matlab Softwareand Successive Difference Method for the Ultrasonic Velocity Using the Resonance Method and Phase method

共振法和相位法可以测量声速,本文使用逐差法处理实验数据以减小实验中的随机误差和仪器误差。实验中测量的物理量较多,人工处理数据比较繁琐,且容易出错。因此,本文使用Matlab软件和逐差法处理数据。把测量的实验数据和仪器不确定度输入Excel表格中,然后把Excel文件引入到Matlab软件中,运行逐差法计算的程序后可以直接得到声速,以及测量的百分差和相对不确定度,处理过程快捷精确。经过计算发现:相位法测量声速的百分差略低于共振法测量声速的百分差。

Ultrasonic velocity can be determined by means of the resonance method and phase method. The ex-perimental data can be processed by the successive difference method,which can decrease the random error and the instrumental error of the system. Many physical parameters are measured and the data process by hands is trivial with high error probability. Therefore,the data is processed with Matlab software. The measured data and the instrumental error of the system in the Excel file can be imported into and processed by the Matlab software using the method of successive difference,and then the ultrasonic velocity can be obtained quickly and precisely with low percentage difference and low relative uncertainty. It turns out that the accuracy of phase method is better than that of resonance method.