Application of a 10 V Programmable Josephson Voltage Standard in Direct Comparison With Conventional Josephson Voltage Standards

This paper briefly describes the working principle of the 10 V programmable Josephson voltage standard (PJVS) that was developed at the National Institute of Standards and Technology and how to use it in a direct comparison with a conventional Josephson voltage standard (CJVS). Manual and automatic comparison methods were developed to verify the agreement between the two types of Josephson standards. A 10 V PJVS provided by the National Aeronautics and Space Administration (NASA) was used as a transfer standard in the 2014 Josephson voltage standard Interlaboratory Comparison that is organized by the National Conference of Standards Laboratories International. The results of automatic direct comparisons between a NASA PJVS and three CJVSs are reported. Allan variance is applied to analyze the large number of correlated data for Type A uncertainty.