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The National Research Council (NRC) of Canada has recently established an alternating-current Josephson voltage standard (ACJVS) system based on the National Institute of Standards and Technology pulse-driven Josephson junction arrays. This paper describes the efforts undertaken at the NRC and the experience that was gained. An experimental method of measuring corrections for the voltage probe lead errors is described, and first results are reported. By introducing the ACJVS, the NRC will be able to reduce the uncertainties of the thermal transfer standard calibration by threefold on the 200-mV range and five- to tenfold on the 20-mV range, in comparison with thermal-converter- and micropotentiometer-based calibrations. [ABSTRACT FROM AUTHOR]

This paper describes a 10 V Josephson Voltage Standard (JVS) direct comparison between the National Institute of Standards and Technology (NIST) and the Instituto Nacional de Metrologia, Normalização e Qualidade Industrial (INMETRO) using automatic data acquisition. The results were in agreement to within 1.1 nV and the mean difference between the two JVSs at 10 V is 0.54 nV with a pooled combined standard uncertainty of 1.48 nV. Considering a recent JVS comparison between NIST and the Bureau International des Poids et Mesures (BIPM), the difference between INMETRO and the BIPM thus was found to be -0.26 nV with a standard uncertainty of 1.76 nV. INMETRO JVS improvements since the 2006 INMETRO-BIPM comparison are also described. [ABSTRACT FROM AUTHOR]