Design and implementation of differential AC voltage sampling system based on PJVS

First, a differential sampling measurement principle is introduced. Based on this principle, we have developed a precision differential sampling system to measure AC voltage with the use of a quantum-accurate AC Programmable Josephson Voltage Standard. The differential sampling system design adopts switching measurement technology. By analysing the error source of the differential sampling system, a mathematical model is established, and the error transfer function is derived. We have performed a variety of measurements to evaluate this differential sampling system. First, the transition is analysed, and the selection scheme of the sampling window is described. After averaging, the uncertainty obtained in the determination of Fluke 5720A 1 V RMS amplitude sine wave at 60 Hz is 0.3 μV/V (type A); the uncertainty obtained in the determination of PJVS 1 V RMS amplitude sine wave at 60 Hz is 0.05 μV/V (type A).