Metrekonvensjonen

The Metre Convention, also known as the Metre Treaty, is an international treaty that establishes a global system of measurement. It was signed on May 20, 1875, by representatives of 17 nations, including France, Italy, Belgium, Spain, Portugal, and the United States. The convention was a response to the need for a standardized system of measurement to facilitate international trade and scientific cooperation.

The Metre Convention established the International Bureau of Weights and Measures (Bureau International des Poids et Mesures, or BIPM) in Sèvres, France, to serve as the world's primary metrology institute. The BIPM is responsible for maintaining the International System of Units (SI), which includes the definitions of the metre, kilogram, second, ampere, kelvin, mole, and candela.

The convention also established the International Prototype of the Metre (IPM), a physical artifact that served as the standard definition of the metre for over a century. In 1960, the IPM was replaced by a definition based on the wavelength of light emitted by krypton-86 atoms, which is more stable and reproducible.

The Metre Convention has been amended several times since its inception to keep pace with advances in science and technology. In 1921, the convention was revised to include the kilogram, second, and ampere as fundamental units. In 2019, the convention was amended again to redefine the kilogram, ampere, kelvin, and mole in terms of fundamental constants of nature.

The Metre Convention remains a cornerstone of the global measurement system, ensuring consistency and comparability of measurements across borders and disciplines. It continues to be an essential tool for facilitating international trade, scientific research, and technological innovation.