In November this year at the General Conference on Weights and Measures it was decided to change the way the kilogram is measured in favour of defining a kilogram in terms of an electric current.
In a secured vault outside of Paris within the Bureau of Weights and Measures (BIPM), a small cylinder of platinum-iridium alloy sits protected by a triple walled glass enclosure. Since 1889, this international prototype kilogram (IPK) or “Le Grand K”, has served as the base unit of mass for all other weights manufactured around the world.
The kilogram is the base unit of mass in the International System of Units (ISI) and is the only unit still defined by a physical artefact. All weights used to calibrate