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Phasor Measurement Units (PMUs) are being deployed on electric power grids to monitor their static and dynamic behavior. The information they gather is important to detect problems on these systems and to prevent blackouts. The PMUs require time synchronization of the data taken across the grids. This is done using Coordinated Universal Time (UTC) usually derived from the Global Positioning System...
In most key and regional comparisons of Josephson voltage standards (JVS) the Type A uncertainty is assumed to be the standard deviation of the mean of the measurand calculated as if repeated measurement values were uncorrelated. In a recent JVS key comparison (BIPM.EM-K10.b) between the Bureau International des Poids et Mesures (BIPM) and the National Institute of Standards and Technology (NIST),...
A direct Comparison between two Josephson Voltage Standard (JVS) systems has been used in the Bureau International des Poids et Mesures (BIPM) key comparisons or regional supplementary comparisons to verify the performance of a JVS with an uncertainty of few parts in 1010. Most direct JVS comparisons were manually operated. Hardware and protocol for an automatic direct JVS comparison have been developed...
This paper describes a 10 V Josephson Voltage Standard (JVS) direct comparison between the National Institute of Standards and Technology (NIST) and the Instituto Nacional de Metrologia, Normalização e Qualidade Industrial (Inmetro) using automatic data acquisition. The results were in agreement to within 1.1 nV and the mean difference between the two JVSs at 10 V is 0.54 nV with a pooled combined...
NIST recently reported the first application of a quantum AC Josephson voltage standard (ACJVS) for calibration of thermal transfer standards in the 1 kHz to 10 kHz frequency range. This paper describes preliminary work on extending its frequency calibration range up to 100 kHz by correcting systematic errors due to voltage leads.
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