Comparison of Josephson array voltage standards by using a portable Josephson transfer standard

Project Description

A comparison of Josephson array voltage standards at the 1-V level will be carried out. It will be an RMO KC supplementing BIPM.EM-K10.a. A portable Josephson array voltage standard of VNIIM will be used as travelling standard. It provides a stable and isolated output voltage like a Zener reference but it is a quantum standard with low noise. Therefore, the portable Josephson array voltage standard allows comparisons with an uncertainty of less than 1 nV.

Final Report 2005-06-07

The comparison has been finished and the results are available in the KCDB.

The comparison was performed in a similar way as the bilateral Josephson voltage standard comparisons of the NMIs with the BIPM (see BIPM.EM-K10.a). As BIPM has also participated in this EUROMET comparison, we have an indirect link to BIPM (NMI - Transfer Standard - Transfer Standard - BIPM). In the KCDB the differences NMI - BIPM are given together with the combined uncertainty of the two measurements. The KCRV is the voltage supplied by the BIPM Josephson voltage standard, and therewith will be the same as for BIPM.EM-K10.a assumed that the output voltage of the BIPM standard will not has changed with time.

At the EUROMET Meeting of the Experts in Electrical DC and Quantum Metrology June 16 to 18, 2003, Bratislava, Slovakia a report of VNIIM and PTB was presented, showing that a suitable travelling standard was available. The comparison then started in October 2003, with PTB as the pilot laboratory, and finished in June 2004. The mandatory value to be measured was 1 V with a 4 Ω output resistance of the portable Josephson voltage standard.

The comparison is registered in the KCDB (identifier EUROMET.EM.BIPM-K10.a) and was approved by the WGLF and the CCEM. The results together with the final report are available on the BIPM website.

Progress Report 2004-03-31

 Expenses for the both delivering the standard to the place of comparison and carrying out of them, as well as travelling and living expenses' of a VNIIM specialist are covered by the party where the comparison take place.