International System of Units
- International System of Units
A
system of measurements, based on the
metric system, adopted at the 11th General Conference on Weights and Measures of the International
Organization for
Standardization (1960) to cover both the coherent units (
basic, supplementary, and derived units) and the decimal multiples and submultiples of these units formed by use of prefixes proposed for general international scientific and technological use. SI proposes seven
basic units:
meter (
m),
kilogram (
kg), second (
s),
ampere (
A),
Kelvin (
K),
candela (
cd), and
mole (
mol) for the
basic quantities of
length,
mass,
time, electric
current,
temperature,
luminous intensity, and amount of
substance, respectively; supplementary units proposed include the
radian (
rad) for
plane angle and
steradian (
sr) for
solid angle; derived units (
e.g.,
force,
power,
frequency) are stated in terms of the
basic units (
e.g.,
velocity is in meters per second, m s
−1). Multiples (prefixes) in
descending order are:
exa- (
E, 10
18),
peta- (
P, 10
15),
tera- (
T, 10
12),
giga- (
G, 10
9),
mega- (
M, 10
6),
kilo- (
k, 10
3),
hecto- (
h, 10
2),
deca- (
da, 10
1),
deci- (
d, 10
−1),
centi- (
c, 10
−2),
milli- (
m, 10
−3),
micro- (
μ, 10
−6),
nano- (
n, 10
−9),
pico- (
p, 10
−12),
femto- (
f, 10
−15),
atto- (
a, 10
−18). Proposed prefixes are zetta- (
z, 10
21), yotta- (
y, 10
24),
zepto- (
z, 10
−21), and yocto- (
y, 10
−24). Those involving a
multiple of 10
3 are recommended; compounds of these are not recommended (
e.g.,
mμ for n). [Fr. Système International d'Unités]
* * *
In·ter·na·tion·al System of Units .int-ər-'nash-nəl-, -ənəl- n an internationally accepted system of units based on the metric system and having the meter, kilogram, second, ampere, kelvin, mole, and candela as base units, the radian and steradian as supplementary units, and deriving all other units from these
abbr. SI called also International System
* * *
see SI unit, under unit.
Medical dictionary.
2011.
Look at other dictionaries:
International System of Units — n. SI … English World dictionary
International System of Units — SI redirects here. For other uses, see Si (disambiguation). Cover of brochure The International System of Units The International System of Units[1] (abbreviated SI from French: Système international d unités[2]) is the modern … Wikipedia
International System of Units — an internationally accepted coherent system of physical units, derived from the MKSA system, using the meter, kilogram, second, ampere, kelvin, mole, and candela as the basic units (SI units) of the fundamental quantities length, mass, time,… … Universalium
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International System of Units (SI) — ▪ Table International System of Units (SI) Base units unit abbreviation physical quantity metre m length second s time kilogram kg mass ampere A electric current kelvin K thermodynamic temperature candela cd luminous intensity mole mol amount of… … Universalium
International System of Units — Tarptautinė vienetų sistema statusas T sritis Standartizacija ir metrologija apibrėžtis Suderintoji matavimo vienetų sistema, kurią patvirtino ir rekomendavo Generalinė svarsčių ir matų konferencija (CGPM – Conférence générale des poids et… … Penkiakalbis aiškinamasis metrologijos terminų žodynas
International System of Units — Tarptautinė vienetų sistema statusas T sritis ekologija ir aplinkotyra apibrėžtis Suderintoji matavimo vienetų sistema, kurią patvirtino ir rekomendavo Generalinė svarsčių ir matų konferencija (CGPM – Conférence générale des poids et mesures).… … Ekologijos terminų aiškinamasis žodynas
International System of Units — noun a complete metric system of units of measurement for scientists; fundamental quantities are length (meter) and mass (kilogram) and time (second) and electric current (ampere) and temperature (kelvin) and amount of matter (mole) and luminous… … Useful english dictionary
International System of Units — noun Date: 1932 a system of units based on the metric system and developed and refined by international convention especially for scientific work abbreviation SI … New Collegiate Dictionary
international system of units — noun the SI system of units … English new terms dictionary
