数据采集系统共模抑制比的测量实验研究  

On the Measurement Experiment of Common Mode Rejection Ratio of Data Acquisition Systems

作　　者：梁志国[1] 冯秀娟[2] LIANG Zhiguo;FENG Xiujuan(National Key Laboratory of Metrology and Calibration Technology,Changcheng Institute of Metrology and Measurement,Beijing 100095,China;Division of Mechanics and Acoustics Metrology,National Institute of Metrology,Beijing 100029,China)

机构地区：[1]北京长城计量测试技术研究所计量与校准技术重点实验室,北京100095 [2]中国计量科学研究院力学与声学计量科学研究所,北京100029

出　　处：《测试技术学报》2024年第2期139-146,共8页Journal of Test and Measurement Technology

基　　金：国家规范修订计划资助项目([2021]237号)。

摘　　要：介绍了数据采集系统共模抑制比参数的概念、内涵及定义,并阐述了数据采集系统共模抑制比测量中的5个问题:1)共模干扰的非线性问题;2)共模干扰表现形式的多样性,即直流偏移形式,交流波动形式,噪声水平变化形式;3)本底噪声影响的测量及剔除方式,即方差(能量)相减方式,有效值差方式,绝对值均值差方式;4)共模信号端接方式的影响;5)直流共模抑制比和交流共模抑制比的差异。以一个典型数据采集系统上的实验结果,阐述了上述不同条件变化对共模抑制比测量结果的影响,给出了数据采集系统共模抑制比测量的技术建议。This paper introduces the concept,connotation and definition of common mode rejection ratio(CMRR)parameter of data acquisition system(DAS),and expounds on several problems in the measurement of CMRR of DAS:1)nonlinear transfer problems of common mode interference;2)Diversity of common mode interference;Namely,DC offset form,AC fluctuation form and noise level change form;3)Measurement and elimination methods of background noise impact;That is,variance(energy)subtraction method,effective value direct subtraction method,and absolute value mean direct subtraction method;4)Influence of termination mode of common mode signal;5)The difference between DC CMRR and AC CMRR.Based on the experimental results of a typical data acquisition system,the influence of the above different conditions on the CMRR measurement results is described,and technical suggestions for CMRR measurement of data acquisition systems are given.

关 键 词：计量学 共模抑制比 计量评价 校准 数据采集系统 

分 类 号：TH701[机械工程—仪器科学与技术]