本文以虚拟仪器技术LabVIEW为软件平台，结合NI-USB6009数据采集卡，对直流电压和信号发生器的正弦波信号分别进行测量和数据采集，对直流电压及正弦信号频率和幅值的测量结果进行统计研究，得到电压、正弦信号频率和幅值的统计结果为正态分布. 对周期信号增加单个周期的采样数，可以减小频率测量的标准差，提高频率测量的准确度. 该实验可以对学生开设为通过实际测量研究随机误差的正态分布规律的实验.

 In this paper, the virtual instrument technology LabVIEW as a software platform, combined with NI-USB6009 data acquisition card is used to measure DC voltage and both the amplitude and the frequency of sine wave of the signal generator. The statistical result of the measurement shows the normal distribution. For the periodic signal, increasing of sampling quantity per period can reduce the standard deviation of the frequency, and can cause improving the accuracy of frequency measurement. This experiment can be designed for students to study the normal distribution law of random error through practical measurement.