Josephson array voltage calibration system: operational use and verification

Abstract

A Josephson array system that maintains the US legal volt is described. This system is almost fully automated, operates with a typical precision of 0.009 mu V, and readily allows US legal volt measurements weekly, or more frequently if desired. This system was compared to the previous volt-maintenance system, and agreement was found to within 0.03 p.p.m. This verification is limited by uncertainties in the resistive divider instruments of the previous system.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>