EEEL RESEARCHERS AND CENAM CARRY OUT A REGIONAL METROLOGY ORGANIZATION (RMO) COMPARISON OF DC JOSEPHSON VOLTAGE STANDARD IN THE SYSTEM INTERAMERICANO DE METROGIA(SIM)

摘要

A comparison of Josephson Voltage Standards (JVS) at 10 V between NIST and the Centra Nacional de Metrologia (CENAM) was carried out at CENAM from March 21-23, 2006. The comparison was made at the 10 V level by measuring four Zener references using the JVS of CENAM and the transportable Compact Josephson Voltage Standard (CIVS) of NIST. This is the first time that the NIST CJVS has been used in SIM bilateral JVS comparison. A set of four Zener standards provided by CENAM was used for transfer during the comparison. The difference between the 24 pairs of Zener measurements was -38 nV with an uncertainty of 42 nV at the 95 percent level of confidence or a relative uncertainty of 4.2 x 10~(-9). The uncertainties of most JVS comparisons using the protocol of the Measurement Assurance Program (MAP), in which Zeners are used as transfer standards for two JVS systems in different locations, are in the range of a few parts in 10~5. The improvement made in this comparison is due to the implementation of the NIST CJVS in the comparison, so that the uncertainty contributions associated with Zener non-ideal behavior, such as nonlinear drift, shipping, and environmental effects from atmospheric pressure, temperature, and relative humidity, are largely eliminated.