We have developed a precision technique to measure sine wave sources with the use of a quantum-accurate ac programmable Josephson voltage standard. This paper describes a differential method that uses an integrating sampling voltmeter to precisely determine the amplitude and phase of high purity and low frequency (a few hundred Hz or less) sine wave voltages. We have performed a variety of measurements to evaluate this differential technique. After averaging, the precision obtained in the determination of the rms amplitude of a 1.2 V sine wave with a frequency of 50 Hz is on the order of 3 parts in 107. Finally, we propose a dual waveform approach for measuring two precision sine waves with the use of a single Josephson system. Currently, NIST is developing a new calibration system for electrical power measurements based on this technique.
Citation: IEEE Transactions on Instrumentation and Measurement
Pub Type: Journals
Digital-analog conversion, Josephson arrays, Quantization, Signal synthesis, Standards, Superconductor-normal-superconductor devices, Voltage measurement, Power Measurement