The International System of Units, universally abbreviated SI, is the modern metric system of measurement. Long the dominant system used in science, the SI is rapidly becoming the dominant measurement system used in international commerce. The definitive international reference on the SI is a document published by the Internat. Bur. of Weights & Measures (BIPM) & often referred to as the SI document. It is in French followed by a text in English. This 2001 ed. is the U.

S. version of the English text of the 7th (most current) ed. of the document. It also incorporates the contents of Supplement 2000: addenda & corrigenda to the 7th ed. (1998), pub. by the BIPM in June 2000.