Precision differential sampling measurements of low frequency voltages synthesized with an AC Programmable Josephson Voltage Standard

Sampling is a promising technique for comparing the stepwise-approximated sine waves synthesized by an AC Programmable Josephson Voltage Standard to the sinusoidal voltages of a secondary source at low frequencies (a few hundred hertz or less). This paper describes a differential method that uses an integrating sampling voltmeter to precisely determine the amplitude and phase of high purity sine wave voltages by comparing them to quantum-accurate waveforms.