A measurement of the NBS electrical watt in SI units

Abstract

The National Bureau of Standards (NBS) electric watt in SI units to be: W/sub NBS//W=K/sub W/=1-(16.69+or-1.33) p.p.m. The uncertainty of 1.33 p.p.m. has the significance of a standard deviation and includes the best estimate of random and known or suspected systematic uncertainties. The mean time of the measurement is May 15, 1988. Combined with the measurement of the NBS ohm in SI units: Omega /sub NBS// Omega =K/sub Omega /=1-(1.593+or-0.022) p.p.m., this leads to a Josephson frequency/voltage quotient of E/sub J/=E/sub 0/(1+(7.94+or-0.67) p.p.m.) where E/sub 0/=483, 594 GHz/V.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>