The dissemination of mass in the United States: Results and implications of recent BIPM calibrations of US National Prototype Kilograms

Published

March 12, 2014

Author(s)

Zeina J. Kubarych, Patrick J. Abbott

Abstract

The National Institute of Standards and Technology (NIST) is responsible for the dissemination of the unit of mass within the United States of America through the national prototype kilogram K20 and its check standard K4. These platinum-iridium artifacts have been in use since 1889 and are periodically sent to the International Bureau of Weights and Measures (BIPM) for recalibration. The following is a brief description of the roles of the national prototype kilograms in the dissemination of mass in the U.S., and the implications for NIST mass calibration customers of the most recent recalibrations of K20 and K4.

Citation

Journal of Research (NIST JRES) - 119.001

Report Number

119.001

NIST Pub Series

Journal of Research (NIST JRES)

Pub Type

NIST Pubs

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DOI Link

Keywords

mass metrology, kilogram, SI unit of mass, dissemination, calibration, national prototypes, mass stability, BIPM calibration, Platinum-Iridium kilograms, national standards, recalibration of US national standard

Citation

Kubarych, Z. and Abbott, P. (2014), The dissemination of mass in the United States: Results and implications of recent BIPM calibrations of US National Prototype Kilograms, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/jres.119.001 (Accessed October 6, 2025)