BIPM

The Bureau International des Poids et Mesures (BIPM) is an intergovernmental organization created by the Metre Convention of 1875 to coordinate global metrology and ensure the universal stability and coherence of measurements. Its headquarters are in Sèvres, France, near Paris. The BIPM serves as the central body in the international system for metrology, working through its governance framework to maintain and develop measurement standards that are used worldwide.

The BIPM operates under two principal governing bodies: the General Conference on Weights and Measures (CGPM) and the International Committee for Weights and Measures (CIPM). The CGPM is the supreme authority and is composed of representatives from member states and associate states. The CIPM provides scientific leadership, develops technical guidance, and appoints the director-general who manages the BIPM’s daily operations. Together, these bodies set policy, approve new definitions, and oversee international comparisons of national measurement standards.

A core mandate of the BIPM is to maintain the International System of Units (SI) and its realizations, publish authoritative references such as the SI Brochure, and coordinate international comparisons to ensure measurement traceability across borders. The organization also houses the International Time Section, which collects data from national time laboratories to compute and disseminate time scales such as International Atomic Time (TAI) and Coordinated Universal Time (UTC). Through these activities, the BIPM supports science, industry, and commerce by providing accurate, globally consistent measurements and timekeeping.

The BIPM collaborates with national metrology institutes and other international organizations to advance measurement science, facilitate trade, and support ongoing discussions about the redefinition or refinement of SI units.