The International system of Units (SI) includes seven base units; the metre, second, kilogram, kelvin, mole, ampere and candela, forming a foundation around which cooperation and collaboration on a global scale can take place.

The SI units have been under constant improvement since the 17th Century when a committee of the French Academy of Sciences introduced the first unified measurement system based on the artefacts for metre and kilogram.

Implementing the revised International System of Units (SI)

Recent advances have now enabled scientists to base the SI units entirely on fundamental properties of nature, which will ensure their ongoing refinement and improvement for years to come.

On 16 November 2018, four of the seven base units will be put forward for redefinition – the kilogram, kelvin, mole, and ampere.

To witness this historic moment join the open session of the General Conference on Weights and Measures (CGPM) at the Palais des Congrès by connecting to the BIPM’s Youtube channel at 11am CET

What is the redefinition?

After decades of ground-breaking laboratory work, the world’s scientific and technical community is about to redefine four of the seven base units for the International System of Units (SI). Watch the video below to find out more.