Overview

A standardized system of units is required for the measurement of physical properties. Over the years, two systems of measurements have been standardized. They are the English system of units, which is still in common use in the United States, and the SI (Syst me International d'Unit s) system of units. However, efforts are being made to standardize on the SI system. The SI units are sometimes referred to as the centimeter-gram-second (CGS) units and are based on the metric system but it should be noted that not all of the metric units are used. The SI system of units is maintained by the Conf rence Gen rale des Poids et Measures. Because both systems are in common use it is necessary to understand both system of units and to understand the relation between them. A large number of units (electrical) in use in the English system are SI units. Table A.1 gives the base units in both systems. Table A.2 gives SI units. Table A.3 gives English units. Table A.4 gives conversion between units. Table A.5 gives a list of some of the metric units that are not used in the SI system.