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  • Summary & Details

New Defi nition of the Kilogram based on the Planck Constant and Its Application to Small Mass, Force and Torque Measurements


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Category(E)Hot Topics
Author(J)1) 藤井 賢一
Author(E)1) Kenichi Fujii
Affiliation(J)1) 国立研究開発法人産業技術総合研究所


Abstract(E)The kilogram had been the last SI base unit still defined by the material artifact. In November 2018, it was adopted to revise the definition by using a defined number of the Planck constant. The new definition comes into force on May 20th, 2019, the World Metrology Day. This historical change in the definition of the unit of mass was realized by the progress of recent measurement technologies in the X-ray crystal density and the watt (Kibble) balance methods. The new definition opens a new way for small mass, force and torque measurements in metrology.

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