Pulse-driven AC Josephson voltage standard at VNIIM

A pulse-driven AC Josephson voltage standard (ACJVS) was developed at VNIIM on the basis of PTB chips. The current margins for ac Josephson steps are wider than 0.7 mA. This system was directly compared with an AC measurement sampling system at the level of 0.5 V and a frequency of 62.5 Hz. A relative voltage difference of 0.3 μV/V with a standard uncertainty 0.03 μV/V was achieved.