In one month's time on the 16th November the meeting of the General Conference on Weights and Measures (CGPM) will take place at the Palais des Congrès in Versailles. It will vote on the adoption of a Resolution that will redefine four of the seven base units of the SI.
This is a historic milestone eagerly awaited by the entire international metrology community and which represents one of the most significant changes to the SI since its creation.
The revision of the SI will not only redefine four of the seven base units (the kilogram, the ampere, the kelvin and the mole) but also mark the end of the link between the SI and an artefact dating from 1889. The last remaining artefact, the International Prototype of the Kilogram, will be formally replaced by a realization in the form of a new experiment linked to the Planck constant.
The International System of Units (SI), which has been the responsibility of the CGPM from the time of its adoption at the 11th CGPM in 1960, superseded the Metric System, which was one of the most enduring legacies of the French Revolution.
Today, the SI is the legal system of units in use in almost all countries around the world, and is the unit system of choice in scientific discourse. This revision of the SI is the culmination of many years of intensive scientific cooperation between the National Metrology Institutes and the International Bureau of Weights and Measures (BIPM).
Martin Milton, Director of the BIPM
26th meeting of the CGPM (2018) website