An improved current-comparator-based power standard at 120 V/5 A, 50 Hz – 60 Hz, with an uncertainty of 2.5 µW/VA (k = 1)

An improved power standard derived from a current comparator power bridge for calibrating active/reactive power and energy meters under sinusoidal conditions is described. Measurements can be made at any power factor from zero lag through unity to zero lead, positive or negative power, at 120 V, 5 A, and 50 or 60 Hz. The improved power standard has an estimated basic uncertainty of 2.5 μW/VA at k = 1.