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SYSI: Symposium Fundamental Constants and new SI

SYSI 1: Fundamental Constants and new SI

SYSI 1.4: Invited Talk

Wednesday, March 13, 2019, 12:00–12:30, U Audimax

The Planck constant and the realization of the kilogram — •Stephan Schlamminger — National Institute of Standards and Technology, Gaithersburg, USA

Up to May 20th this year, there was one mass on earth that we knew with zero uncertainty. This mass is the international prototype of the kilogram (IPK). On May 20th, the IPK will be just another mass and the mass unit will be defined via a fixed value of the Planck constant, which will be fixed to the value of h=6.62607015× 10⁻³⁴⁾ J s with zero uncertainty on this day. In this presentation, I will explain how the kilogram, the unit of mass can be realized via the Kibble balance and the X-ray crystal density method.