The international system of units (SI)

The resolutions and recommendations of the General Conference on Weights and Measures (CGPM) on the International System of Units are published herein. Explanations have been added as well as relevant extracts from the International Standards of the International Organization for Standardization (ISO) for the practical use of the System. Appendix I reproduces in chronological order the decisions promulgated since 1889 by the CGPM and the International Committee for weights and measures (CIPM) on units of measurement and on the International System of Units. Appendix II outlines the measurements, consistent with the theoretical definitions given here, which metrological laboratories can make to realize the units and to calibrate precision material standards. This 3d edition is the second edition brought up to date with the decisions of the 15th CGPM (1975) and the amendments made by the CCU at its 4th and 5th sessions (1974 and 1976) and by the CIPM at its session of September 1976.