About metrology

Metrology is the science of measurement. A measurement always involves a comparison of an unknown quantity with a quantity whose properties are known (standard or reference material). In this regard, determining measurement uncertainty plays an essential role in the reliability of the measurement.

About metrology

International agreements

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.

Traceable measurement

Measurements should be traceable to fixed standards in order to be able to compare measurement results at different locations or times. We can only establish a new world marathon record if the measurements made in that regard are comparable. The same goes for greenhouse gas emissions. If we agree on country-by-country emissions, we need to take measurements in the same way in order to be able to draw conclusions.

National metrology institutes manage and ensure traceability to the primary standards, which enable us to compare the measurements made. In the Netherlands, VSL is responsible for this, providing calibrations with those standards and producing reference materials resulting from them.

The importance of metrology for innovation

New technologies almost always require accurate measurements. Consider, for example, the precise radiotherapy needed for cancer, the application of nanotechnology in chip production and the generation and transmission of energy. This requires ever higher accuracy and reliability of existing measurements. For example, a split second in online stock market trading makes a crucial difference to a transaction.

New developments require new measurement standards. For example, the ultimate cold fuel LNG (Liquefied Natural Gas) requires a primary standard for measuring it. VSL operates the calibration facility where LNG meters are examined under these conditions.