The International System of Units (SI), Physical Quantities, and Their Dimensions

Abstract

international system of units In this chapter, we introduce the International System of Units (SI) on the basis of the SI brochure “Le Système international d'unités (SI)” [2.1], supplemented by [2.2]. We give a short review of how the SI was worked out and who is responsible for the further development of the system. Following the above-mentioned publications, we explain the concepts of base physical quantities and derived physical quantities on which the SI is founded, and present a detailed description of the SI base units and of a large selection of SI derived units. We also discuss a number of non-SI units non-SI units which still are in use, especially in some specialized fields. A table (Table 1.2-17) presenting the values of various energy equivalents closes the section.