A constant from a mass, a mass from a constant

Published

November 9, 2014

Author(s)

Jon R. Pratt, Stephan Schlamminger, David B. Newell, Leon S. Chao, Zeina J. Kubarych, Patrick J. Abbott, Yusi A. Cao, Frank C. Seifert, Darine El Haddad

Abstract

NIST recently used a watt balance instrument known as NIST-3 to measure the Planck constant in terms of IPK with a relative uncertainty of approximately 45 parts in 10e9. Along the way to this new NIST value of h, the instrument was also employed to perform the reciprocal experiment: h was “fixed” and the unknown mass of a stainless steel mass standard was “calibrated” with reference only to standards of length, time (frequency), and electrical quantities, all derivable from fixed fundamental constants. This paper reviews the basic principles of a watt balance experiment and shares the results of a trial dissemination of mass directly from an instrument, rather than from an artifact.

Proceedings Title

ASPE Annual Meeting Proceedings

Conference Dates

November 9-15, 2014

Conference Location

Boston, MA

Conference Title

29th Annual Meeting of the American Society of Precision Engineering

Pub Type

Conferences

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Keywords

watt balance, kilogram, SI, quantum electrical standards

Citation

Pratt, J. , Schlamminger, S. , Newell, D. , Chao, L. , Kubarych, Z. , Abbott, P. , Cao, Y. , Seifert, F. and El, D. (2014), A constant from a mass, a mass from a constant, ASPE Annual Meeting Proceedings, Boston, MA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=917043 (Accessed October 25, 2025)