TABLE OF CONTENTS G.L.Moln r 1 , R.B.Firestone 2
1 Institute of Isotope and Surface Chemistry, Chemical Research Center, Budapest, Hungary
2 Isotopes Project, Lawrence Berkeley National Laboratory, Berkeley, California, USA
The modern metric system of measurement has become the standard in scientific practice. The official name is International System of Units, abbreviated SI from the French Le Syst me International d Unit s . The SI was established in 1960 by the 11th General Conference on Weights and Measures. The defining document, commonly called the SI Brochure, has been published by the International Bureau of Weights and Measures (BIPM) in French original and in English translation (BIPM 1991). It has been complemented with a series of international consensus standards to promote international uniformity in the practical use of the SI in science and technology (ISO 1993). Several national standards organizations have prepared practical guides to promote the implementation and practical use of the SI in their country. This chapter is mainly based on the guide prepared by the National Institute of Standards and Technology (NIST), USA (Taylor 1995), which is also available electronically on the NIST website on constants, units and uncertainty (NIST 2003).
There are two classes of SI units: base units and derived units. The system is founded on seven base units for seven base quantities, which are assumed to be mutually independent. They are given in TABLE 1. The definition of the SI base units can...
