The accuracy of the rate or frequency of an atomic time scale is the degree to which its unit agrees with the SI second. Primary frequency standards are constructed in such a manner that t,hey provide the most accurate possible physical realization of the SI second. These standards are then used to calibrate or construct an atomic time scale which may also be used as a stable reference standard...

− This paper is focused on the problems related to the calibration of the reactive energy meters on the place of installation of the electricity meter (on-site), using the load of the same electrical system. In the presence of harmonic distortion, the behaviour of the meters can go out of the limits imposed by the theoretical calibration curve, depending on the metric used by both reference sta...

We report on multiple improvements made in the calibration services offered for thermal converters and thermal transfer standards in the ac-dc Difference Standards and Measurement Techniques Project at NIST during the past year. The major improvement in this calibration is the increased efficiency made possible by the consolidation of three disparate calibration services – low voltage thermal t...