Error and Uncertainty Estimations for A Passive-CC-Based AC Current Ratio Standard at High Audio Frequencies

This paper describes a development framework for alternating current ratio standard working at high audio frequencies. To realize this, first, a calibration method for frequency-dependent balancing current generators (BCGs) producing error currents to balance current comparators (CCs) is proposed. Second, the BCG error correction is made not only for the current transformer (CT) calibration but also for the CC self-calibration. Third, practical capacitive error corrections are also proposed to be introduced for the CT and CC calibrations. Finally, in consideration of the BCG error, capacitive error, and compensated CC error, a proposed way of calculating CT error and estimating its uncertainty is described.