Planck Constant Determination from Power Equivalence

Published

April 1, 2000

Author(s)

David B. Newell

Abstract

Equating mechanical to electrical power links the kilogram, the meter, and the second to the practical realizations of the ohm and the volt derived from the quantum Hall and the Josephson effects, yielding an SI determination of the Planck constant. The NIST watt balance uses this power equivalence principle, and in 1998 measured the Planck constant with a combined relative uncertainty of 8.7 x 10^-8, the most accurate determination to date. The next generation of the NIST watt balance is now being assembled. Modification to the experimental facilities have been made to reduce the uncertainty components from vibrations and electromagnetic interference. A vacuum chamber has been installed to reduce the uncertainty components associated with performing the experiment in air. Most of the apparatus is in place and diagnostic testing of the balance should begin this year. Once a combined relative uncertainty of one part in 10^-8 has been reached, the power equivalence principle can be used to monitor the possible drift in the artifact mass standard, the kilogram, and provide an accurate alternative definition of mass in terms of fundamental constants

Proceedings Title

Abstract, Bulletin Amer. Physical Society

Volume

45

Issue

2

Conference Dates

April 28-May 2, 2000

Conference Location

Long Beach, CA

Pub Type

Conferences

Keywords

Planck, constant, fundamental constants, kilogram, watt, balance, mass, standard

Citation

Newell, D. (2000), Planck Constant Determination from Power Equivalence, Abstract, Bulletin Amer. Physical Society, Long Beach, CA (Accessed April 26, 2024)