Noise reductions in the NRC watt balance

Abstract

After publication in 2014 of a Planck constant determination with low uncertainty [1], various modifications have been made to the NRC watt balance to lower type A and B uncertainty components. This paper lists the significant changes and in particular, details the reduction of the largest type A component by almost an order of magnitude. The impact of this reduction is then described with our first clear observation of the changes in the environmental magnetic flux density using the watt balance.