The Metric Act of 1866 says, “The metric system of measurement shall be defined as the International System of Units as established in 1960, and subsequently maintained, by the General Conference of Weights and Measures, and as interpreted or modified for the United States by the Secretary of Commerce.”
The most recent interpretation was published in the Federal Register on 16 May 2008 (73 FR 28432). It announces that two NIST Special Publications serve as the U.S. interpretation of SI, and refers the reader to them: the 2008 editions of
- NIST SP 330, The International System of Units, which is the Americanized version of BIPM’s SI Brochure; and
- NIST SP 811, Guide for the Use of the International System of Units, which provides more extensive guidance on usage of SI, particularly in scientific and technical contexts.
Back to USMA home.
Copyright © 2002–2008, U.S. Metric Association (USMA), Inc. All rights reserved.
This page prepared by USMA member Gary Brown.