# International System of Units

Officially called the Système International d’Unités, or SI,
system of units adopted by the 11th General Conference on Weights and Measures (1960).
It is based on the metric system. The basic units of
length, mass, and time are those of the mks system of
metric units: the meter, kilogram, and second. Other basic units are the ampere of
electric current, the kelvin of temperature (a degree of temperature measured on
the Kelvin temperature scale), the candela, or candle, of luminous intensity, and
the mole, used to measure the amount of a substance present. All other units are
derived from these basic units.

#### see: U.S. National Bureau of Standards, Spec. Pub. 330, International System of Units (1971).

source: The Columbia Encyclopedia, Sixth Edition. 2001.