Limitation of the Artifact-Based Definition of the Kilogram, its Redefinition and Realization Using Kibble Balance

摘要

Until recently, the kilogram was the only SI base unit having an artifact as its primary standard. For more than four decades, there have been continuous efforts worldwide toward redefining the kilogram, the SI unit of mass, to have an artifact-independent and time-invariant definition based on a fundamental constant. Due to the effort of metrologists across the globe, on 16th November 2018, in the 26th meeting of the General Conference on Weights and Measure (CGPM), the kilogram was finally redefined based on the Planck constant. This paper gives an overview of the limitations of an artifact-based definition and the significance of the redefinition, and, its implications. The principle of the Kibble balance and its major components and their role is also discussed.