交流电压源毫伏级量值准确测量的技术研究

基于电压比例和交直流转换技术,提出了一种对交流电压源的毫伏级量值进行准确测量的方法。采用自行研制的二进制级联结构电压比例装置和792A交直流转换标准,将被测交流电压源的毫伏级量值溯源至交流电压国家基准。实验采用替代测量法,通过选用不同电压比例和不同792A量程的组合,在55Hz~5kHz频率范围内,对1台5720A多功能校准源10~200mV范围的交流电压进行准确测量。结果表明,各毫伏级交流电压示值相对误差的绝对值均不超过±40μV/V,测量结果扩展不确定度优于80μV/V,满足交流电压源毫伏级量值溯源需求。

Research on the Technology of AC Voltage Source at mV Level

An accurate calibration method of millivolt AC voltage source based on voltage proportional and AC/DC transfer technology is proposed. The binary cascaded voltage proportional device and 792A AC/DC transfer standard are adopted to trace the millivolt AC voltage to a known AC voltage. By using a substitution measurement method,and choosing the combination of different voltage proportion and different range of 792A, the AC voltage in the range of 10~200mV of a 5720A multifunctional calibration source is accurately measured in the frequency range of 55Hz~5kHz. Results show that the relative error of any measured millivolt AC voltage is within ±40μV/V, and the expanded uncertainty is better than 80μV/V, which shows that the proposed method can meet the traceability requirements of millivolt AC voltage source.