Organisation of metrology in France. Cofrac – French Accreditation Body

Consider the International Vocabulary of Metrology – Fundamental and General Concepts and Associated Terms (abbreviated to VIM). Metrology is the science of measurement and its applications.

In other words, the process of experimentally obtaining one or more values that can reasonably be attributed to a quantity.

If we ask ChatGPT today, this artificial intelligence tells us that the main aim of metrology is to ensure the traceability of measurements, i.e. to guarantee that measurement results can be traced back to recognized reference standards. This helps to establish confidence in measurements made in one place, and facilitates the comparison and exchange of information on a global scale.

VIM explains that metrological traceability is the property of a measurement result whereby it can be related to a reference through an unbroken, documented chain of calibrations, each of which contributes to the uncertainty of measurement.

In the context of this article, the treatment of metrology will be limited to the tip of the iceberg, i.e. calibration. It should be remembered that conformity assessment (ISO/CEI 17000 § 2.1) does not explicitly cover calibration services. However, for the sake of consistency and technical competence, accreditors at international level (ILAC P10) require the use of either a national metrology institute (NMI/INM) or an accredited calibration laboratory, in order to guarantee measurement accuracy or uncertainty when these affect the validity of reported results.

Accreditation, on the other hand, is the process of assessing, recognizing and accrediting the competence of an organization. In the field of conformity assessment, accreditation mainly concerns analysis laboratories, testing laboratories, inspection bodies and, to a lesser extent, certification bodies (systems, products and personnel).