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The 2008 NCSLi Josephson Voltage Standards Interlaboratory Comparison



Harold V. Parks, William B. Miller, Leonard P. Pardo, Curtis Kiser, Clark A. Hamilton, Yi-hua D. Tang, Barry M. Wood


Josephson voltage standards (JVS) provide a highly accurate representation of the volt. Although the Josephson Effect provides an intrinsic standard of voltage, inter-comparisons between different systems are important to insure that potential sources of systematic error are under control and to provide an explicit link to the volt as maintained by a national metrology institute. We present results from the 8th Josephson voltage standards inter-laboratory comparison (ILC) at 10 V sponsored by the National Conference of Standards Laboratories International (NCSLi). The inter-laboratory comparison was conducted between March and July 2008 with 14 participating labs in North America. It began with a direct array to array comparison between the National Institute of Standards and Technology (NIST) compact Josephson voltage standard (CJVS) system and the system at the pivot lab at Lockheed Mission Services in Denver. The two systems agreed to well within the k = 2 uncertainty of the comparison of 6.6 nV at 10 V [1]. Once the NIST-pivot lab comparison was complete, four traveling Zeners were sent from the pivot lab to the participant labs in a series of four loops with a pivot lab measurement between the loops. The standard deviation of the 10 V bank average as measured by the participants with respect to the drift line established by the pivot lab was 68 nV. There are some indications of non-normal behavior in the residuals and we adopt an expanded uncertainty for the comparison of 190 nV at a 95% level of confidence.
Proceedings Title
Conference Proceedings of NCSL International Workshop and Symposium
Conference Dates
July 26-30, 2009
Conference Location
San Antonio, TX, US


direct comparison, Josephson voltage standard, uncertainty, Zener traveling standard


Parks, H. , Miller, W. , Pardo, L. , Kiser, C. , Hamilton, C. , Tang, Y. and Wood, B. (2009), The 2008 NCSLi Josephson Voltage Standards Interlaboratory Comparison, Conference Proceedings of NCSL International Workshop and Symposium, San Antonio, TX, US, [online], (Accessed May 25, 2024)


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Created June 30, 2009, Updated October 12, 2021