Resolution 12 of the 11th CGPM (1960)
Système International d'Unités
The 11th Conférence Générale des Poids et Mesures (CGPM),
considering
- Resolution 6 of the 10th CGPM, by which it adopted six base units on which to establish a practical system of measurement for international use:
length metre m mass kilogram kg time second s electric current ampere A thermodynamic temperature degree Kelvin °K luminous intensity candela cd - Resolution 3 adopted by the Comité International des Poids et Mesures (CIPM) in 1956,
- the recommendation adopted by the CIPM in 1958 concerning an abbreviation for the name of the system, and prefixes to form multiples and submultiples of the units,
decides
- the system founded on the six base units above is called the "Système International d'Unités";
- the international abbreviation of the name of the system is SI;
- names of multiples and submultiples of the units are formed by means of the following prefixes:
Multiplying factor Prefix Symbol 1 000 000 000 000 = 10^{12} tera T 1 000 000 000 = 10^{9} giga G 1 000 000 = 10^{6} mega M 1 000 = 10^{3} kilo k 100 = 10^{2} hecto h 10 = 10^{1} deca da Multiplying factor Prefix Symbol 0.1 = 10^{–1} deci d 0.01 = 10^{–2} centi c 0.001 = 10^{–3} milli m 0.000 001 = 10^{–6} micro µ 0.000 000 001 = 10^{–9} nano n 0.000 000 000 001 = 10^{–12} pico p - the units listed below are used in the system, without excluding others which might be added later.
Supplementary units
Plane angle | radian | rad |
Solid angle | steradian | sr |
Derived units
area | square metre | m^{2} | |
volume | cubic metre | m^{3} | |
frequency | hertz | Hz | 1/s |
mass density (density) | kilogram per cubic metre | kg/m^{3} | |
speed, velocity | metre per second | m/s | |
angular velocity | radian per second | rad/s | |
acceleration | metre per second squared | m/s^{2} | |
angular acceleration | radian per second squared | rad/s^{2} | |
force | newton | N | kg · m/s^{2} |
pressure (mechanical stress) | newton per square metre | N/m^{2} | |
kinematic viscosity | square metre per second | m^{2}/s | |
dynamic viscosity | newton-second per square metre | N · s/m^{2} | |
work, energy, quantity of heat | joule | J | N · m |
power | watt | W | J/s |
quantity of electricity | coulomb | C | A · s |
tension (voltage), difference, electromotive force | volt | V | W/A |
electric field strength | volt per metre | V/m | |
electric resistance | ohm | Ω | V/A |
capacitance | farad | F | A · s/V |
magnetic flux | weber | Wb | V · s |
inductance | henry | H | V · s/A |
magnetic flux density | tesla | T | Wb/m^{2} |
magnetic field strength | ampere per metre | A/m | |
magnetomotive force | ampere | A | |
luminous flux | lumen | lm | cd · sr |
luminance | candela per square metre | cd/m^{2} | |
illuminance | lux | lx | lm/m^{2} |
DOI : 10.59161/CGPM1960RES12E
The reader should note that the official version of this Resolution is the French textNOTE
The CGPM later abrogated certain of its decisions and extended the list of prefixes:
- The name and symbol for the unit of thermodynamic temperature were modified by the 13th CGPM in 1967 (Resolution 3).
- A seventh base unit, the mole, was adopted by the 14th CGPM in 1971 (Resolution 3).
- Further prefixes were adopted by the 12th CGPM in 1964 (Resolution 8), the 15th CGPM in 1975 (Resolution 10), and the 19th CGPM in 1991 (Resolution 4).
- The 20th CGPM in 1995 abrogated the class of supplementary units in the SI (Resolution 8). These are now considered as derived units.
- The 13th CGPM in 1967 (Resolution 6) specified other units which should be added to this list of derived units. In principle, the list is without limit.
- Modern practice is to use the phrase "amount of heat" rather than "quantity of heat", because the word quantity has a different meaning in metrology.
- Modern practice is to use the phrase "amount of electricity" rather than "quantity of electrcity" (see above).