An analytical model for designing permanent magnet systems in watt and joule balances

摘要

Permanent magnets with yokes are widely used in the watt and joule balances to measure the Planck constant for the forthcoming redefinition of the unit of mass, the kilogram. Recently, a permanent magnet system has been in consideration for a further practice of the generalized joule balance. In this paper, an analytical model to design the permanent magnet system is presented. The presented model can be used as a guidance to design and optimize such magnetic systems.