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Revolutionizing the System of Units

PTB-News 1.2018

The International System of Units (SI) is being fundamentally revised. The foremost expert committee in the world of metrology, the International Committee for Weights and Measures (Comité international des poids et mesures, CIPM), issued its fundamental recommendation for this development at its recently concluded annual assembly. It is hoped that, at their general conference in November 2018, the international community of signatories to the Metre Convention will heed the experts’ advice and provide the physical units with an especially firm foundation – one that consists of the set values of selected fundamental constants. The seven base units will thereby lose their prominent role. Instead, seven fundamental constants will be determined as defining reference entities from which all units can be derived.

The key date on which the new definitions are formally to enter into force is World Metrology Day (20 May), 2019. Nothing about our daily lives is expected to change. The kilogram will be just as heavy on 20 May as it was on 19 May. However, daily life in advanced technological fields will look somewhat different. There, the new, highly innovation-friendly definitions are sure to bring noticeable benefits. You will find much more complementary information about this topic on our website at: Opens internal link in current windowPTB > Opens internal link in current windowResearch & Development > Opens internal link in current windowResearch on the new SI