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Uncertainty Improvements of the NIST Electronic Kilogram


Richard L. Steiner, Edwin R. Williams, Ruimin Liu, David B. Newell


This paper summarizes the latest uncertainty improvements in the NIST Electronic Kilogram experiment to obtain result of 7 +/- 37 nW/W for the ratio {W90/W -1} (and the Planck constant), comparable to the NIST 2005 value but with a lower uncertainty. Of the eight largest Type B uncertainty contributions, gravity acceleration, wheel surface, and magnetic susceptibility have been reduced). Humidity dependence in the recent data, limitations on the volt/velocity signal, and mass reference stability are now the main limitations on the uncertainty.
IEEE Transactions on Instrumentation and Measurement


absolute power unit, electronic kilogram, fundamental physical constants, Planck constant, watt balance


Steiner, R. , Williams, E. , Liu, R. and Newell, D. (1970), Uncertainty Improvements of the NIST Electronic Kilogram, IEEE Transactions on Instrumentation and Measurement (Accessed May 23, 2024)


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Created August 26, 2016, Updated January 27, 2020