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Metric Convention

Metric Convention (MC) is an international inter-governmental treaty signed on May 20th, 1875 (today the International Day of Metrology) by representatives of 17 counties (inclusive the Austria-Hungary). In July 2014 this organization had 56 (full) members and 41 associated ones. The Membership fee of the CR currently is ca 57 000 EUR.

The main goal of the Metric Convention was to establish a universal decimal system of units as required by a fast progress of science, manufacture and trade in the middle of the 19th  century. The Convention, slightly amended in 1921, has since that time become a platform for international unification of units of measurement, for development of physical standards and to ensure their equivalence – the organization administers the International system of units SI (Le Système international d´unités), today universally used across the world to establish metrological traceability of measurement results – details of the SI system of units are given at

The treaty gave rise to the following bodies: International Bureau of Weights and Measures (BIPM), General Conference of Weights and Measures (CGPM) and International Committee of Weights and Measures (CIPM).  You can find more information about the bodies of the Metric Convention at

Those interested can download from this web-site here a full text of the Metric Convention as published by the Decree of the Ministry of Foreign Affair no. 200/1924 Coll. (in the original spelling and wording) here. Additional details about the MC and its bodies can be found at the BIPM web-site .

The Czech Republic, as a country of succession of the Austria-Hungary, is a signatory of the MC since the very beginning and some Czech national standards derive their metrological traceability, among others, from international standards maintained in BIPM.

In October 1999 directors of 38 national metrology institutes (NMI) of the member states of the Metric Convention (inclusive CMI) and of 2 international organizations (IRMM, IAEA) signed an Arrangement on mutual recognition of national measurement standards and of calibration and measurement certificates issued by NMIs (Mutual Recognition Arrangement, MRA) drawn up by the committee CIPM – see The term  "Arrangement" has been used to indicate that this document is not legally binding. The aim of this Arrangement create a sound basis in the area of national measurement standards for their mutual recognition and elimination of barriers in international trade both in the framework of WTO and on a bilateral basis. From the technical point of view the arrangement is based on a system of international comparisons of national measurement standards (so called key and supplementary comparisons) and on implementation and acceptance of quality management systems against requirements of ISO 17025:2005 in NMIs. One of the outcomes is a database of so called Calibration and Measurement Capabilities - CMC - see "Key Comparison Database" (KCDB)  at It contains an extensive range of data for all fields of measurement that come into consideration. For the Czech Metrology Institute a successful participation in key comparisons is extremely important and it is an approved policy of CMI to participate to a maximum possible extent. Currently, CMI has ca 400 lines of CMCs which is the rank 6 in Europe after the 4 biggest countries and the Netherlands.