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CCU President explains in interview series why we need the SI redefinition

Measurement community prepares for constant evolution of the International System of Units

Just a few days ago the measurement community celebrated World Metrology Day.The theme 'Constant evolution of the International System of Units' was chosen because in November 2018, the General Conference on Weights and Measures is expected to agree one of the largest changes to the International System of Units (SI) since its inception in 1875.

Constant evolution
The SI is structured around seven base units. It is anticipated that four of the seven base units (the kilogram, ampere, kelvin and the mole) will be redefined according to fixed values of natural constants. This will aid access to the agreed values for worldwide measurements and underpin future requirements for increases in accuracy. Redefinition, if agreed, will come into effect on World Metrology Day, 20 May 2019.

International effort
The work needed to reach this point has taken many years, and has been an international effort. Amongst those working towards the redefinition is Prof Dr Joachim Ullrich, President of PTB, Germany's National Measurement Institute.

Joachim is also Vice-President of the International Committee for Weights and Measures (CIPM). The Committee consists of eighteen people nominated for their high level of understanding in the field. The CIPM is responsible for decisions about the SI with the goal of creating a reliable basis for measurements that can be used now and into the future.

The CIPM is advised by the Consultative Committee for Units. In his role as President of the Consultative Committee, Joachim, along with the other committee members, is active in matters related to the development of the SI.

In addition, Joachim chairs the according task group for the promotion of the SI.

Video series explains what is behind redefinition
Despite his heavy workload, Joachim took the time to talk to EURAMET about the importance of the SI, the expected redefinition and the resulting potential for innovation.

The outcome is a comprehensive lecture and a series of short, easy explained video interviews on topics including

The individual video interviews will be published over the next few weeks.
Subscribe to our YouTube channel and don't miss a single episode https://www.youtube.com/user/EURAMET/

Are you interested in more technical details? Then have a look at Joachim's comprehensive lecture on the SI and the expected redefinition recorded by EURAMET.

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