Minimization of the coil movement of the LNE watt balance during weighing mode and estimation of parasitic forces and torques involved

Alignments of watt balance experiments are necessary to achieve a relative uncertainty at a level of few parts in 108. This paper briefly describes the LNE watt balance and concentrates on adjustments made to minimize the coil movements during weighing mode. The parasitic forces and torques involved in these movements are estimated by a mathematical model. Some of the calculated parasitic forces are compared with an evaluation done by studying the yaw movement of the beam.