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Title: Invited Article: A precise instrument to determine the Planck constant, and the future kilogram

Abstract

A precise instrument, called a watt balance, compares mechanical power measured in terms of the meter, the second, and the kilogram to electrical power measured in terms of the volt and the ohm. A direct link between mechanical action and the Planck constant is established by the practical realization of the electrical units derived from the Josephson and the quantum Hall effects. We describe in this paper the fourth-generation watt balance at the National Institute of Standards and Technology (NIST), and report our initial determination of the Planck constant obtained from data taken in late 2015 and the beginning of 2016. A comprehensive analysis of the data and the associated uncertainties led to the SI value of the Planck constant, h = 6.626 069 83(22) × 10{sup −34} J s. The relative standard uncertainty associated with this result is 34 × 10{sup −9}.

Authors:
; ;  [1];  [2]; ; ; ; ;  [1]
  1. National Institute of Standards and Technology (NIST), 100 Bureau Drive Stop 8171, Gaithersburg, Maryland 20899 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22597953
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 87; Journal Issue: 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
29 ENERGY PLANNING, POLICY AND ECONOMY; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; BALANCES; COMPARATIVE EVALUATIONS; ECONOMICS; HALL EFFECT; METERS; PLANCK LAW

Citation Formats

Haddad, D., E-mail: darine.haddad@nist.gov, Seifert, F., Williams, C., University of Maryland, Joint Quantum Institute, College Park, Maryland 20742, Chao, L. S., Li, S., Newell, D. B., Pratt, J. R., and Schlamminger, S., E-mail: stephan.schlamminger@nist.gov. Invited Article: A precise instrument to determine the Planck constant, and the future kilogram. United States: N. p., 2016. Web. doi:10.1063/1.4953825.
Haddad, D., E-mail: darine.haddad@nist.gov, Seifert, F., Williams, C., University of Maryland, Joint Quantum Institute, College Park, Maryland 20742, Chao, L. S., Li, S., Newell, D. B., Pratt, J. R., & Schlamminger, S., E-mail: stephan.schlamminger@nist.gov. Invited Article: A precise instrument to determine the Planck constant, and the future kilogram. United States. doi:10.1063/1.4953825.
Haddad, D., E-mail: darine.haddad@nist.gov, Seifert, F., Williams, C., University of Maryland, Joint Quantum Institute, College Park, Maryland 20742, Chao, L. S., Li, S., Newell, D. B., Pratt, J. R., and Schlamminger, S., E-mail: stephan.schlamminger@nist.gov. 2016. "Invited Article: A precise instrument to determine the Planck constant, and the future kilogram". United States. doi:10.1063/1.4953825.
@article{osti_22597953,
title = {Invited Article: A precise instrument to determine the Planck constant, and the future kilogram},
author = {Haddad, D., E-mail: darine.haddad@nist.gov and Seifert, F. and Williams, C. and University of Maryland, Joint Quantum Institute, College Park, Maryland 20742 and Chao, L. S. and Li, S. and Newell, D. B. and Pratt, J. R. and Schlamminger, S., E-mail: stephan.schlamminger@nist.gov},
abstractNote = {A precise instrument, called a watt balance, compares mechanical power measured in terms of the meter, the second, and the kilogram to electrical power measured in terms of the volt and the ohm. A direct link between mechanical action and the Planck constant is established by the practical realization of the electrical units derived from the Josephson and the quantum Hall effects. We describe in this paper the fourth-generation watt balance at the National Institute of Standards and Technology (NIST), and report our initial determination of the Planck constant obtained from data taken in late 2015 and the beginning of 2016. A comprehensive analysis of the data and the associated uncertainties led to the SI value of the Planck constant, h = 6.626 069 83(22) × 10{sup −34} J s. The relative standard uncertainty associated with this result is 34 × 10{sup −9}.},
doi = {10.1063/1.4953825},
journal = {Review of Scientific Instruments},
number = 6,
volume = 87,
place = {United States},
year = 2016,
month = 6
}
  • The best measurement of the Planck constant is now derived from the watt balance method. This method measures mechanical power, in reference units of the kilogram (artifact mass standard), second (atomic clocks), and meter (lasers), in ratio to electrical power, in reference units of the volt (Josephson effect) and ohm (quantum Hall effect). Of these reference standards, only the kilogram is still an artifact standard. Thus a high precision measurement of the Planck constant is equivalent to monitoring the SI kilogram artifact, and may be used to redefine the kilogram. This talk will summarize the complexity of making a Planckmore » constant measurement, where there are interesting aspects of basic physics that appear when the ultimate precision of the standards laboratory is applied to obtain an uncertainty of 20 parts in a billion.« less
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