Comparison of AC Power Referenced to Either PJVS or JAWS

The results of a comparison on active power meter calibrations at the National Institute of Standards and Technology (NIST) using a source of ac power referenced to either a programmable Josephson voltage standard (PJVS) or a Josephson arbitrary waveform synthesizer (JAWS) is presented. The measurements were made at 60 V rms, 5 A rms, and 50 Hz at a power factor of 1.0. The estimated uncertainty of the active power applied to a meter under test (MUT) of the two system configurations is within 2 μW/VA (k = 1), and the comparison results demonstrate that the two system configurations agree to within 1 part in 106 for applied voltage, current, and phase. A discussion of the measurement techniques and major sources of error is given for applied power signals over the 50-Hz-6-kHz frequency range.