The International System of Units (SI), which defines standard units such as the kilogram, metre and second, forms the basis for all sciences. According to Noor Abdulhussain, one of the Sisters in Science and an employee at the Dutch Metrology Institute VSL, this is essential. ‘World Metrology Day reflects on the basis for international cooperation in metrology and the foundation laid for the SI system. This is also very important for chemistry, ensuring that terms such as “1 mole” or “1 milligram per litre” have the same meaning everywhere.’

Metrology is the science of measurement, Abdulhussain explains. ‘t covers everything that has units. It’s not just about measuring; it’s also about the measurement results.’ In metrology, we work to create a reliable and certain infrastructure for measurement results, so you can be sure that when you fill up your car with 1 litre of fuel, you are actually getting 1 litre. This is calibrated using metrology.’

Calibration is an important part of the work at VSL, as is the creation of reference standards. Abdulhussain herself works on the MetCCUS project at VSL, which focuses on CO₂ capture and storage. ‘For applications such as these, VSL develops reference materials for CO₂ mixtures, as well as calibration and measurement methods, so the industry can accurately determine the composition of gas mixtures before storing them in the North Sea.’

‘As metrologists, we really need to be at the forefront of society in this respect’, Abdulhussain continues. ‘When you talk about the energy transition to hydrogen, for example, you need to know the exact quantity and quality of the hydrogen gas, and whether it contains any contaminants and, if so, how much.’

Abdulhussain recognises that the field is not yet very visible. ‘When I tell people about metrology, they often think of meteorology first. That’s why World Metrology Day is a great opportunity to reflect on the importance of reliable measurements in our society, and to raise awareness of the work we do at VSL.’