International Bureau of Weights and Measures

International Bureau of Weights and Measures (short: BIPM ) is the German name of the French Bureau International des Poids et Mesures (abbreviated: BIPM). The BIPM is to provide an international organization with the task of a globally uniform and unambiguous system of measures based on the International System of Units.

Survey

The BIPM was founded together with the Metre Convention on 20 May 1875 and operates under the auspices of the " International Committee for Weights and Measures " (see " CIPM "). It has its headquarters in Sèvres, near Paris, France. Every four years the General Conference on Weights and Measures held (see " CGPM " ), in which the central issues of the BIPM to be decided.

To ensure the uniformity of dimension and unit system coordinates the BIPM, the representations of the unit normal of various national metrology institutes ( " National Metrological Institute" in short, NMI). The SI second is based for example on an atomic constant of nature. Worldwide, more time institutes the SI second with the aid of atomic clocks represent the BIPM takes over the balance of these representations. For units which are defined by a physical standard ( or were), the BIPM in addition is responsible for keeping the reference body, for example, the kilogram standard ( prototype kilogram ) in the form of a platinum - iridium cylinder, or until 1960 by the meter Normal ( standard meter ) used platinum -iridium rod.

International Committee

The International Committee for Weights and Measures ( French " Comité International des Poids et Mesures " in short, CIPM ) is made up of 18 people from various of the Metre Convention acceded countries. The CIPM meets annually at the BIPM.

General Conference

The International General Conference on Weights and Measures (from the French " Conférence Générale des Poids et Mesures "; short CGPM ) is the highest organ of the Metre Convention. It takes place at a distance of four to six years, you include delegates from all the signatory states. The first meeting took place in 1889. There, meters, kilograms and seconds were ( comparable with current SI units) defined as an international base units.