Classical Nonquantum AC Power Measurements With Uncertainties Approaching 1 ${\rm \mu}\hbox{W/VA}$

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A recent upgrade of the primary standard for electric alternating power at the Physikalisch-Technische Bundesanstalt improved the measurements, indicating that standard uncertainties of the order of 1 <formula formulatype="inline"><tex>${\rm \mu}\hbox{W/VA}$</tex></formula> are attainable. Investigations done to ensure such low uncertainty figures are presented, and the evaluation of measurement uncertainties is discussed in detail. </para>