The Physikalisch-Technische Bundesanstalt (PTB) is the national metrology institute providing scientific and technical services. PTB measures with the highest accuracy and reliability – metrology as the core competence.

PTB performs fundamental research and development work in the field of metrology as a basis for all the tasks entrusted to it in the areas concerning the determination of fundamental and natural constants, the realization, maintenance and dissemination of the legal units of the SI, safety engineering, services and metrology for the area regulated by law and for industry, as well as technology transfer. Only fundamental research work performed by PTB itself using latest technologies will enable it to ensure on a long-term basis its metrological competence recognized on the international level, and to extend it further.

The application of modern management tools enables PTB to perform the tasks entrusted to it efficiently and thoroughly. For the long term, PTB's work program has been adapted to the requirements of its clients - trade and industry, science and society - also within the European framework. The initiation of project work guarantees flexibility when problems are to be solved on a short-term basis.

As a result of its close cooperation with universities, other research institutes and industry, PTB has become a member of the community of all those pursuing research in Germany, and it makes use of these links for the benefit of all those involved. The comparison with the national metrology institutes of other countries ensures constant critical assessment at the highest level of metrology. Together with our partners in the projects implemented within the scope of international cooperation, PTB ensures the comparability and reliability of measurement results everywhere in the world on a long-term basis.

Participation with an Ex Proficiency Testing Scheme is essential for the compliance of the requirements of ISO/IEC 17025 and IECEx regarding the need of the Ex laboratories to perform interlaboratory comparisons. In addition, the results of Ex PT programs will contribute considerably to the development of the "Peer concept" within the global community of Ex laboratories. With the practical experience gained in its performance, the PTB Ex Proficiency Testing Scheme shall be further developed and improved (continuous improvement process). The vision is to extend the PT scheme step by step to all fields of conformity assessment (not only testing) within the scope of the IEC/TC31 standards. The results of this IECEx Proficiency Testing Scheme will also be of direct use for all participants, among others for:

• proving the competence to
  • customers,
  • regulators, and
  • end users
• the identification and avoidance of problems in and between the test laboratories and the initiation of measures for improvement
• the establishment of the effectiveness and comparability of the applied testing and measurement methods
• the provision of additional confidence to the customer
• the avoidance of distortions of competition between the manufacturers as the customers of the test laboratories
• the further promotion of the "fair play" culture.

The implementation of this Ex PT scheme will allow to detail test methods (required by the applicable IEC standards) in "Best Practice Papers" (to be published on this website), providing continuous improvement of the performance of the IECEx system.