In practically all countries in the world, fair trade is being supported by legal regulations made on measurements, measuring instruments and the use of measured values, and the trust of citizens in official measurements is being strengthened. Furthermore, legally regulated measurements also serve legal security and help to prevent any possible economic damage that might be caused, e.g. during cross-border trade with natural gas or petroleum. Only by means of internationally uniform requirements made on measuring instruments and measurement conditions can it be ensured that measuring instruments in different countries indicate the same values within defined maximum permissible errors. Furthermore, in times of globalization, it is important to regulate – in a uniform and binding way – not only technical requirements made on measuring instruments, but also test procedures, test reports and certificates. This is the task of international and regional (for example European) organizations like the OIML (Organisation Internationale de Métrologie Légale) and WELMEC (European Legal Metrology Cooperation).
The international agreements between the national metrology institutes on the mutual recognition of calibrations, conformity assessments and certificates, (CIPM-MRA and OIML-MAA) contribute very successfully to the fact that technical and administrative obstacles to global trade and international technical cooperation are clearly reduced, partially even completely eliminated. However, the increasing emergence of confidence-building processes within the scope of these agreements to detect the competence of the participating partners, for example key comparisons and mutual assessments, requires an improvement in the process execution and in its quality management. PTB strives for a revision of the CIPM-MRA, it is a member of the respective working groups in the CIPM and will elaborate – in cooperation with other national metrology institutes – proposals to ensure the future practicability and effectiveness of the agreements.
At the European level, PTB will continue to participate intensively in the committees of legal metrology, for example WELMEC and NoBoMet (Cooperation of Notified Bodies for European Measuring Instruments) in order to avoid distortions of competition for German manufacturers and possible disadvantages for German consumers. Also in international committees, e.g. in OIML, WELMEC and COOMET, PTB will – in the coming years – contribute to the objective of being able to represent the interests of German industry and of the German consumers. Hereby, especially the extension of the OIML Mutual Acceptance Arrangement (OIML-MAA) has to be mentioned, which allows the German manufacturers of measuring instruments to access the market in many countries more easily. In cooperation with other national metrology institutes, these activities will further advance the international harmonization of legal metrology.
With the entering into force of the new Measures and Verification Act (MessEG) on 1 January 2015, legal metrology in Germany was completely restructured and consistently adapted to European directives, e.g. to the European Directive 2004/22/EC on measuring instruments (MID), as well as to international developments. For example, a conformity assessment body for the type examination of more than 150 measuring instrument categories was set up at PTB in 2014, the "Rule Determination Committee" was founded and the Committee of the Conformity Assessment Bodies was introduced. The leadership and management of these new bodies was assigned to PTB. It is especially due to these functions that PTB can fulfill its legal task to ensure consistency in metrology in Germany. The successful implementation of the new Measures and Verification Act (MessEG) will also be supported by PTB by rendering intensive consultation services to the authorities of the German federal states which are in charge of metrology, as well as to manufacturers of measuring instruments.
Particular challenges in the examination and testing of legally controlled measuring instruments are their increasing modularity and complexity as well as the software-controlled functionality and interconnectivity, up to the updating of software via the Internet and the storage of protected data in a cloud. Measuring instruments are increasingly operated in networks, for example networked weighing instruments, measuring instruments in manufacturing plants, or communicative utility meters for domestic use ("smart meters"). Here, the need arises to drive the standardization of communication and data formats forward. The European Measuring Instruments Directive MID and the new Measures and Verification Act (MessEG) stipulate the elaboration of procedures for risk analysis and risk assessment for measuring instruments communicating via the Internet. At the same time, requirements must be developed which have to be met by measuring instruments during remote enquiry, software updating or remote maintenance via the Internet. PTB is increasingly engaged in elaborating recommended procedures for manufacturers of measuring instruments, conformity assessment bodies and organizations of market and user surveillance, and is perceived as a competence center at the European level.
A current and socially and economically important example of the variety of legally regulated measuring instruments is exhaust meters. For example, the EU directive on the EURO-6 standard specifies exhaust-gas limits of internal combustion engines in passenger cars and utility vehicles. To check the newly specified limit values, exhaust meters must reliably determine both the number of particles and the particle size. Various methods of particle counting and particle size classification are used for this purpose. The validation of these methods is the precondition for the conformity assessment of modern exhaust meters. PTB is driving forward, for this purpose, the respective apparative developments of the technical equipment.
According to the new Measures and Verification Act, PTB is still exclusively responsible for the conformity assessment of those types of measuring instruments which serve the measurement of the dose of ionizing radiation. Due to the upcoming adaptation of the national Radiation Protection Act to European Law, an introduction of the measurands Hp(3) and H'(3) is to be expected. In the case of the introduction of these additional radiation protection measurands, PTB will characterize its specific reference radiation fields accordingly in order to be able to carry out conformity assessments and calibrations of local and area dosimeters.