The International System of Units

Pages: 123 (30579 words) / Published: May 8th, 2013
The International System of Units
And its base units

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Contents
Articles
Overview
International System of Units 1 1 20 20 30 35 37 39 39 42 51 69 75 78 82 86 90 90 93

Organisations
Metre Convention General Conference on Weights and Measures International Bureau of Weights and Measures International Committee for Weights and Measures

Base units
SI base unit Metre Kilogram Second Ampere Kelvin Mole Candela

Apprendix
SI derived unit Units accepted for use with SI

References
Article Sources and Contributors Image Sources, Licenses and Contributors 95 98

1

Overview
International System of Units
For a topical guide to this subject, see Outline of the metric system. The International System of Units (abbreviated SI from French: Le Système international d 'unités) is the modern form of the metric system. It comprises a coherent system of units of measurement built around seven base units, 22 named and an indeterminate number of unnamed coherent derived units, and a set of prefixes that act as decimal-based multipliers. The standards, published in 1960, are based on the metre-kilogram-second system, rather than the centimetre-gram-second system, which, in turn, had several variants. The SI has been declared to be an evolving system; thus prefixes and units are created and unit definitions are modified through international agreement as the technology of measurement progresses, and as the precision of measurements improves. SI is the world 's most widely used system of measurement, used in both everyday commerce and science.[1][2][3]

The seven SI base units and the interdependency of their definitions. Clockwise from top: kelvin (temperature), second (time), metre (length), kilogram (mass), candela (luminous intensity), mole (amount of substance) and

Citations: 32 Associates At its 21st meeting (October 1999), the CGPM created the category of "associate" for those states not yet members of the BIPM and for economic unions.[1]