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PTB supports BIPM towards on-site AC Josephson intercomparisons


More and more National Metrology Institutes (NMI) are using Programmable Josephson Voltage Standards (PJVS) to extend their quantum-based voltage calibration services into AC. The International Bureau of Weights and Measures (BIPM) has started to expand the present protocol for DC on-site intercomparisons to eventually include AC measurements. During a recent BIPM visit to PTB, different measurement parameters and set-ups were tested.



As more and more NMIs make the transition from their established “traditional” Josephson voltage standards to PJVS, they are also extending their measurement capabilities from DC into AC voltages. PTB among other leading NMI in the field of Josephson voltage standards as KRISS (KR), NIST (US), NMI Australia (AU) and VNIIM (RU) are presently collaborating with BIPM in studies that will lead to the protocol for future international on-site comparisons including AC voltages. Within these collaborations, different possible measurement configurations are tested.

Over the last two years PTB has hosted expert staff from BIPM for measurement campaigns of several weeks of duration in order to jointly test a variety of experimental set-ups and to investigate the influence of relevant measurement parameters (see publication). Most recently, additional instruments that could be used as transfer standards between the two PJVS being compared were evaluated, as well as the possibility of using an additional voltmeter that continuously monitors the output of the transfer standard.

S. Solve et. al., “Towards a BIPM on-site comparison program for AC voltages based on the differential sampling technique”, CPEM 2018 Conf. Digest, Paris, July 2018.