Abstract
Unwanted magnetic effects must be minimized and quantified in precision weighing and mass metrology. To this end, methods of measuring magnetic fields and of characterizing the magnetic properties of bodies such as weights are reviewed. The results of comparisons between weights made of ferromagnetic and weakly magnetic materials as well as modelling the magnetic forces between weight and balance are reported. Finally, the impact of the magnetic properties of the weights on regulations in legal metrology is discussed.