The Measurement Uncertainty Evaluation of AC Common Mode Rejection Ratio of Data Acquisition Aystems by Using Averaging Method
LIANG Zhi-guo1,FENG Xiu-juan2
1. National Key Laboratory of Metrology and Calibration Technology, Changcheng Institute of Metrology and Measurement, Beijing 100095,China
2. Institute of Mechanics and Acoustic Metrology, National Institute of Metrology, Beijing 100029, China
Abstract It is described that the uncertainty of evaluation results of AC common mode rejection ratio (CMRR) of data acquisition systems (DAS) by using averaging methods, the interference is calculated by using the means of the absolute sampling data, and the base noise is also calculated as the same method. Then the base noise is cancelled from interference by using direct picking out, and the courses of analysis and evaluation of uncertainty is discussed. Some error sources of CMRR evaluation are discussed, including the signal errors, the gain errors of DAS, the amplitude measuring errors of DAS, the resolution of DAS, the repeatability errors, and the others. The uncertainty model of CMRR of DAS is given out. Combine with an example of experiment, the uncertainty evaluation results of CMRR by using the proposed method is presented.
LIANG Zhi-guo,FENG Xiu-juan. The Measurement Uncertainty Evaluation of AC Common Mode Rejection Ratio of Data Acquisition Aystems by Using Averaging Method[J]. Acta Metrologica Sinica, 2023, 44(11): 1749-1754.
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2023, Vol. 44 
