It is imperative that we use the same standards in international trade. Otherwise, a bolt produced in one country would never fit a nut from another country, for example. Since 1960, the SI system (Système Internationale), or metric system, has been the official basis for measurements, meaning that we use the same units of measurement both nationally and internationally.
This system defines seven SI base units: second (time), metre (length), kilogram (mass), Kelvin (temperature), candela (luminous intensity) mole (amount of substance), and ampere (electric current). These are fundamental units for physical quantities adopted and recommended by the General Conference on Weights and Measures (CGPM: Conférence Générale des Poids et Mesures). All other SI units can be derived from these base units.
In 1999, VSL signed the Mutual Recognition Arrangement (CIPM MRA) of the Bureau Internationale des Poids et Mesures (BIPM) on behalf of the Netherlands, along with many other countries. In it, the signatory countries agreed to accept each other’s national standards and measurement results based on them.