The **General Conference on Weights and Measures** is the English name of the **Conférence générale des poids et mesures** (**CGPM**, never GCWM). It is one of the three organizations established to maintain the International System of Units (SI) under the terms of the Convention du Mètre (Metre Convention) of 1875. It meets in Paris every four to six years. In 2002 the CGPM represented 51 member states and ten further associate members ^{(1)}. As of 2005, the number of associates has grown to 17. Cover of brochure The International System of Units. ...
The Convention du MÃ¨tre of May 20, 1875 is an international treaty that established what is now known as the SI system of units. ...
1875 (MDCCCLXXV) was a common year starting on Friday (see link for calendar). ...
Part of the Paris skyline with from left to right: Montparnasse Tower, Eiffel Tower, and in the background, towers of neighboring La DÃ©fense. ...
For album titles with the same name, see 2002 (album). ...
2005 is a common year starting on Saturday of the Gregorian calendar. ...
## CGPM Meetings - 1
^{st} (1889) - kilogram defined as mass of the international prototype kilogram (IPK) made of platinum-iridium and kept at the International Bureau of Weights and Measures (Bureau international des poids et mesures), Sèvres, France. International prototype metre sanctioned. - 2
^{nd} (1897) - 3
^{rd} (1901) - Litre redefined as volume of 1 kg of water. Clarified that kilograms are units of mass, "standard weight" defined, standard acceleration of gravity defined endorsing use of grams force and making them well-defined. - 4
^{th} (1907) - carat = 200 mg adopted. - 5
^{th} (1913) - International Temperature Scale proposed. - 6
^{th} (1921) - Metre Convention revised. - 7
^{th} (1927) - Consultative Committee for Electricity (CCE) created. - 8
^{th} (1933) - need for absolute electrical unit identified. - 9
^{th} (1948) - ampere, coulomb, farad, henry, joule, newton, ohm, volt, watt, weber defined. Chose degree Celsius from among the three names then in use. l (lowercase L) adopted as symbol for litre. Both the comma and dot on a line are accepted as decimal marker symbols. Symbols for the stere and second changed [1]. - 10
^{th} (1954) - kelvin, standard atmosphere defined. *International System of Units* (metre, kilogram, second, ampere, kelvin, candela) began. - 11
^{th} (1960) - metre redefined in terms of wavelengths of light. Hertz, lumen, lux, tesla adopted. New metric system given the official symbol **SI** for **Système International d'Unités**, the "modernized metric system". Prefixes *pico-*, *nano-*, *micro-*, *mega-*, *giga-* and *tera-* confirmed. - 12
^{th} (1964) - original definition of litre = 1 dm³ restored. *atto-* and *femto-* prefixes. - 13
^{th} (1967) - second redefined as duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom at a temperature of 0 K. *Degree Kelvin* renamed *kelvin*. Candela redefined. - 14
^{th} (1971) - new SI base unit mole defined. Pascal, siemens approved. - 15
^{th} (1975) - *peta-* and *exa-* prefixes. Gray and becquerel radiological units. - 16
^{th} (1979) - candela, sievert defined. Both l and L provisionally allowed as symbols for litre. - 17
^{th} (1983) - metre redefined in terms of the speed of light, but keeps same length. - 18
^{th} (1987) - conventional values adopted for Josephson constant, *K*_{J}, and von Klitzing constant, *R*_{K}, preparing the way for alternate definitions of the ampere and kilogram. - 19
^{th} (1991) - new prefixes *yocto-*, *zepto-*, *zetta-* and *yotta-*. - 20
^{th} (1995) - supplementary SI units (radian and steradian) become *derived units*. - 21
^{st} (1999) - new SI derived unit, the katal = mole per second, for the expression of catalytic activity. - 22
^{nd} (2003) - both the comma and dot on a line are reaffirmed as decimal marker symbols [2]. 1889 (MDCCCLXXXIX) was a common year starting on Tuesday (see link for calendar). ...
The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ...
General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Atomic mass 195. ...
General Name, Symbol, Number iridium, Ir, 77 Chemical series transition metals Group, Period, Block 9, 6, d Appearance silvery white Atomic mass 192. ...
The International Bureau of Weights and Measures is the English name of the Bureau international des poids et mesures (BIPM, often written in English Bureau International des Poids et Mesures), a standards organization, one of the three organizations established to maintain the International System of Units (SI) under the terms...
Road to SÃ¨vres, Jean-Baptiste Camille Corot, 1855-1865. ...
1897 (MDCCCXCVII) was a common year starting on Friday (see link for calendar). ...
1901 (MCMI) was a common year starting on Tuesday (see link for calendar) of the Gregorian calendar (or a common year starting on Wednesday of the 13-day-slower Julian calendar). ...
The litre or liter (see spelling differences) is a unit of volume. ...
The acceleration due to gravity denoted g (also gee) is a non-SI unit of acceleration defined as exactly 9. ...
1907 (MCMVII) was a common year starting on Tuesday (see link for calendar) of the Gregorian calendar (or a common year starting on Wednesday of the 13-day-slower Julian calendar). ...
The carat is a unit of mass used for gems, and equals 200 milligrams or 3. ...
1913 (MCMXIII) was a common year starting on Wednesday. ...
1921 (MCMXXI) was a common year starting on Saturday (see link for calendar). ...
1927 (MCMXXVII) was a common year starting on Saturday (link will take you to calendar). ...
1933 (MCMXXXIII) was a common year starting on Sunday (link will take you to calendar). ...
1948 (MCMXLVIII) was a leap year starting on Thursday (the link is to a full 1948 calendar). ...
A multimeter can be used to measure current The ampere (symbol: A) is the SI base unit of electric current. ...
The coulomb (symbol: C) is the SI unit of electric charge. ...
The farad (symbol: F) is the SI unit of capacitance. ...
An inductor. ...
The joule (symbol: J) is the SI unit of energy, which is defined as the potential to do work. ...
The newton (symbol: N) is the SI unit of force. ...
The ohm (symbol: Î©) is the SI unit of electric resistance. ...
Josephson junction array chip developed by NIST as a standard volt. ...
The watt (symbol: W) is the SI derived unit of power, equal to one joule per second. ...
In physics, the weber (symbol: Wb) is the SI unit of magnetic flux. ...
The Celsius scale is a temperature scale named after the Swedish astronomer Anders Celsius (1701 â€“ 1744), who first proposed a similar system two years before his death. ...
The cubic metre (symbol m³) is the SI derived unit of volume. ...
Look up second in Wiktionary, the free dictionary. ...
1954 (MCMLIV) was a common year starting on Friday of the Gregorian calendar. ...
The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zeroâ€”the lowest possible temperature where nothing could be colder and no heat energy remains in a substanceâ€”is defined as zero kelvin (0 K). ...
Atmospheric pressure is the pressure caused by the weight of air above any area in the Earths atmosphere. ...
The metre, or meter (US), is a measure of length. ...
The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ...
Look up second in Wiktionary, the free dictionary. ...
A multimeter can be used to measure current The ampere (symbol: A) is the SI base unit of electric current. ...
The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zeroâ€”the lowest possible temperature where nothing could be colder and no heat energy remains in a substanceâ€”is defined as zero kelvin (0 K). ...
The candela (symbol: cd) is the SI base unit of luminous intensity (that is, power emitted by a light source in a particular direction, with wavelengths weighted by the luminosity function, a standardized model of the sensitivity of the human eye). ...
1960 (MCMLX) was a leap year starting on Friday (the link is to a full 1960 calendar). ...
The hertz (symbol: Hz) is the SI unit of frequency. ...
The lumen (symbol: lm) is the SI unit of luminous flux. ...
The lux (symbol: lx) is the SI derived unit of illuminance or illumination. ...
The tesla (symbol T) is the SI derived unit of magnetic flux density (or magnetic induction). ...
The International System of Units (abbreviated SI from the French phrase, SystÃ¨me International dUnitÃ©s) is the most widely used system of units. ...
1964 (MCMLXIV) was a leap year starting on Wednesday (the link is to a full 1964 calendar). ...
The litre or liter (see spelling differences) is a unit of volume. ...
1967 (MCMLXVII) was a common year starting on Sunday of the Gregorian calendar (the link is to a full 1967 calendar). ...
General Name, Symbol, Number caesium, Cs, 55 Chemical series alkali metals Group, Period, Block 1, 6, s Appearance silvery gold Atomic mass 132. ...
1971 (MCMLXXI) was a common year starting on Friday (the link is to a full 1971 calendar). ...
The SI system of units defines seven SI base units: physical units defined by an operational definition. ...
The mole and its simple conversions into different units of measurements. ...
The pascal (symbol Pa) is the SI unit of pressure. ...
The siemens (symbol: S) is the SI derived unit of electric conductance. ...
1975 (MCMLXXV) was a common year starting on Wednesday. ...
The gray (symbol: Gy) is the SI unit of absorbed dose. ...
The becquerel (symbol Bq) is the SI derived unit of radioactivity, defined as the activity of a quantity of radioactive material in which one nucleus decays per second. ...
This page refers to the year 1979. ...
The candela (symbol: cd) is the SI base unit of luminous intensity (that is, power emitted by a light source in a particular direction, with wavelengths weighted by the luminosity function, a standardized model of the sensitivity of the human eye). ...
The sievert (symbol: Sv) is the SI derived unit of dose equivalent. ...
1983 (MCMLXXXIII) was a common year starting on Saturday of the Gregorian calendar. ...
1987 (MCMLXXXVII) was a common year starting on Thursday of the Gregorian calendar. ...
The magnetic flux quantum Φ0 is the quantum of magnetic flux passing through a superconductor. ...
The quantum Hall effect is a quantum mechanical version of the Hall effect, observed in two-dimensional systems of electrons subjected to low temperatures and strong magnetic fields, in which the Hall conductance σ takes on the quantized values where e is the elementary charge and h is Plancks...
1991 (MCMXCI) was a common year starting on Tuesday of the Gregorian calendar. ...
Yocto (symbol y) is a SI prefix in the SI system of units denoting a factor of 10-24. ...
Zepto (symbol z) is a prefix in the SI system of units denoting a factor of 10-21. ...
Zetta (symbol Z) is a SI prefix in the SI (system of units) denoting 1021 or 1 000 000 000 000 000 000 000. ...
Yotta (symbol Y) is a SI prefix in the SI (system of units) denoting 1024 or 1 000 000 000 000 000 000 000 000. ...
1995 (MCMXCV) was a common year starting on Sunday of the Gregorian calendar. ...
The radian is a unit of plane angle. ...
The steradian (ste from Greek stereos, solid) is the SI derived unit of solid angle, and the 3-dimensional equivalent of the radian. ...
1999 (MCMXCIX) was a common year starting on Friday, and was designated the International Year of Older Persons by the United Nations. ...
Katal is the SI derived unit for catalytic activity. ...
The mole and its simple conversions into different units of measurements. ...
Look up second in Wiktionary, the free dictionary. ...
2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ...
## See also The Institute for Reference Materials and Measurements or IRMM, located in Geel, Belgium, is one of the seven institutes of the Joint Research Centre (JRC), a Directorate-General of the European Commission (EC). ...
The National Institute of Standards and Technology (NIST, formerly known as The National Bureau of Standards) is a non-regulatory agency of the United States Department of Commerceâ€™s Technology Administration. ...
## References ^{(1)} CGPM Member States |