Uncertainty analysis for ac-dc difference measurements with the AC Josephson voltage standard

A detailed analysis of the uncertainties obtained in ac-dc difference measurements with an AC Josephson voltage standard (ACJVS) is presented. For audio frequencies and for voltages less than 200 mV, ac-dc transfers with the ACJVS may reduce the combined uncertainty by factors of 2-10, compared with conventional methods based on thermal converters. Type A uncertainties are predominantly limited by the thermal transfer standard (TTS), or the digital voltmeter used to acquire the output voltage from the TTS. In agreement with earlier work, the transmission line is the primary contributor to Type B errors for frequencies above 10kHz. A Monte Carlo sensitivity analysis is used to demonstrate how the uncertainties of transmission line impedance and on-chip inductance impact the accuracy of the rms amplitude conveyed to the TTS.