There are two aspects to metrology: scientific and industrial metrology on the one hand, and legal metrology on the other.
Scientific and industrial metrology involves researching, developing and maintaining reference standards, and improving and disseminating the means, methods and knowledge needed to ensure the consistency of measurements made by the various users of measuring instruments, in particular laboratories and companies.
Legal metrology has been defined by the International Organization of Legal Metrology as "that part of metrology which relates to those activities which result from regulatory requirements and which apply to measurements, units of measurement, measuring instruments and are carried out by competent bodies".
Legal metrology, the modern form of weights and measures control, covers all the technical and administrative procedures put in place by public authorities to guarantee the quality and fairness of measurements made in commercial transactions, tax operations or in the fields of health, road safety or the environment.
This article focuses on the second part of the organization of metrology in France. Firstly, it highlights the significant development of legal metrology since its inception, both in France and abroad, with the introduction of the international system of units and the European "new approach" directives.
It then presents national regulations and the various categories of regulated measuring instruments. The control system in place is described in detail, including the principles of organization and the monitoring actions carried out in the field.
It concludes with a presentation of the key players in both government and industry, from manufacturers to holders, as well as control and standardization bodies, and organizations at European and international level.