SP 811, NIST SPECIAL PUBLICATION: GUIDE FOR THE USE OF INTERNATIONAL SYSTEM OF UNITS (SI) (1995)

SP 811, NIST SPECIAL PUBLICATION: GUIDE FOR THE USE OF INTERNATIONAL SYSTEM OF UNITS (SI) (1995)., The International System of Units, universally abbreviated SI is the modern metric system of measurement. Long the dominant measurement system used in science, the SI is becoming the dominant measurement system used in international commerce. The Omnibus Trade and Competitiveness Act of August 1988 [Public Law (PL) 100-418] changed the name of the National Bureau of Standards (NBS) to the National Institute of Standards and Technology (NIST) and gave to NIST the added task of helping United States industry increase its competitiveness in the global marketplace. It also recognized the rapidly expanding use of the SI by amending the Metric Conversion Act of 1975 (PL 94-168). In particular, section 5164 (Metric Usage) of PL 100-418 designates the metric system of measurement as the preferred system of weights and measures for United States trade and commerce and requires that each Federal agency, by a date certain and to the extent economically feasible by the end of fiscal year 1992, use the metric system of measurement in its procurements, grants, and other business-related activities, except to the extent that such use is impractical or is likely to cause significant inefficiencies or loss of markets for United States firms. In January 1991, the Department of Commerce issued an addition to the Code of Federal Regulations entitled "Metric Conversion Policy for Federal Agencies," 15 CFR 1170, which removes the voluntary aspect of the conversion to the SI for Federal agencies and gives in detail the policy for that conversion. Executive Order 12770, issued in July 1991, reinforces that policy by providing Presidential authority and direction for the use of the metric system of measurement by Federal agencies and departments. Because of the importance of the SI to both science and technology, NIST has over the years published documents to assist NIST authors and other users of the SI, especially to inform them of changes in the SI and in SI usage. For example, this second edition of the Guide replaces the first edition prepared by Arthur O. McCoubrey and published in 1991. That edition, in turn, replaced NBS Letter Circular LC 1120 (1979), which was widely distributed in the United States and which was incorporated into the NBS Communications Manual for Scientific, Technical, and Public Information, a manual of instructions issued in 1980 for the preparation of technical publications at NBS.