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Preparation for the introduction of the revised SI in the field of electricity and magnetism

04.04.2017

The Consultative Committee for Electricity and Magnetism (CCEM) of the Convention of the Meter took preparatory steps for the introduction of the revised SI at its 30th meeting from March 22 to 24, 2017. Care was taken that the change to the revised SI will require only minimum efforts by the users of electrical units.

 

 

The 30th meeting of the Consultative Committee for Electricity and Magnetism (CCEM) of the Convention of the Meter was held at the Bureau International de Poids et Mesures (BIPM) in Paris from March 22 to 24, 2017. The members of the CCEM are the national metrology institutes which actively work in electricity and magnetism, among them the PTB. The CCEM meets on a biannual schedule.


In this year´s meeting, particular attention was paid to the preparation for the introduction of the revised International System of Units, the SI. The revised SI will be defined by seven carefully selected constants. In turn, the base units and derived units can be linked to those defining constants. It is expected that the revised SI will be adopted by the General Conference of the Meter Convention in 2018 and implemented on May 20, 2019, which is World Metrology Day.


The revised SI is universal, stable in time, and open to innovations which improve the realization and dissemination of the units. It allows the electrical units to be disseminated as true SI units at the highest metrological level. The transition to the revised SI will cause a maximum change of the disseminated electrical units of 0.1 parts per million. This change will not have practical consequences for most users of electrical units. The few users, whose work is affected by the small change, will be given guidelines by the CCEM how to deal with the change in a way which is metrologically correct, yet requires only minimum effort. The CCEM is presently elaborating these guidelines and will publish them in due time for the implementation of the revised SI.