International Bureau of Weights and Measures
The International Bureau of Weights and Measures (French: Bureau international des poids et mesures, BIPM) is an intergovernmental organisation, through which its 59 member-states act on measurement standards in areas including chemistry, ionising radiation, physical metrology, as well as the International System of Units (SI) and Coordinated Universal Time (UTC).[1] It is based in Saint-Cloud, near Paris, France. The organisation has been referred to as IBWM (from its name in English) in older literature.[note 1]
Abbreviation
Structure[edit]
The BIPM is overseen by the International Committee for Weights and Measures (French: Comité international des poids et mesures, CIPM), a committee of eighteen members that meet normally in two sessions per year,[3] which is in turn overseen by the General Conference on Weights and Measures (French: Conférence générale des poids et mesures, CGPM) that meets in Paris usually once every four years, consisting of delegates of the governments of the Member States[4][5] and observers from the Associates of the CGPM. These organs are also commonly referred to by their French initialisms.
History[edit]
The BIPM was created on 20 May 1875, following the signing of the Metre Convention, a treaty among 17 Member States (as of November 2018 there are now 59 members).[6]
It is based at the Pavillon de Breteuil in Saint-Cloud, France, a 4.35 ha (10.7-acre) site (originally 2.52 ha or 6.2 acres)[7] granted to the Bureau by the French Government in 1876. Since 1969 the site has been considered international territory, and the BIPM has all the rights and privileges accorded an intergovernmental organisation.[8] This status was further clarified by the French decree No 70-820 of 9 September 1970.[7]
The BIPM has the mandate to provide the basis for a single, coherent system of measurements throughout the world, traceable to the International System of Units (SI). This task takes many forms, from direct dissemination of units to coordination through international comparisons of national measurement standards (as in electricity and ionising radiation).
Following consultation, a draft version of the BIPM Work Programme is presented at each meeting of the General Conference for consideration with the BIPM budget. The final programme of work is determined by the CIPM in accordance with the budget agreed to by the CGPM.
Currently, the BIPM's main work includes:[9][10]
The BIPM is one of the twelve member organisations of the International Network on Quality Infrastructure (INetQI), which promotes and implements QI activities in metrology, accreditation, standardisation and conformity assessment.[11]
The BIPM has an important role in maintaining accurate worldwide time of day. It combines, analyses, and averages the official atomic time standards of member nations around the world to create a single, official Coordinated Universal Time (UTC).[12]
