Possible definition of the unit of mass and fixed values of the fundamental physical constants

Abstract

Ways of increasing the accuracy of the values of the Planck and Avogadro constants in experiments with Watt balances and crystalline silicon spheres are examined. These are needed for the new definitions of the kilogram and mole. The advantages and disadvantages of fixing the values of a number of fundamental physical constants when introducing definitions of the SI units are discussed, in particular a new definition of the unit of mass based on a fixed value of the Avogadro constant.