Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Uncertainty Improvements of the NIST Electronic Kilogram

Author(s)

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

Abstract

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.
Citation
IEEE Transactions on Instrumentation and Measurement

Keywords

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

Citation

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)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created August 26, 2016, Updated January 27, 2020