An Evaluation of Josephson-Effect Voltage Standard for the US Army: A Preliminary Report

The experimental procedure used and the results obtained on the evaluation of the Josephson-Effect Voltage (JEV) Standard at the US Army Primary Standards Laboratory (APSL) are reported. The inherent precision of measurement is 0.62 ppm (3σ). The accuracy of the final result which is determined by various uncertainties is about 1 ppm. The Josephson junction (J-J) is used as a frequency-to-voltage converter with a conversion factor equal to 2e/h. The adopted value of 2e/h is 483593.420 GHz/V(NBS).