Study of magnetic properties of standard weights used in Australia

摘要

As electromagnetic compensated comparators are widely used in mass metrology and precision weighing, magnetic interactions between the weights and the balances need to be considered. A recent OIML document on legal metrology [1] gives the upper limits for the magnetic properties of weights, such as magnetic susceptibility and magnetization. In this paper, measurements of these two properties made at the National Measurement Institute (NMI) on samples of standard weights over the last two years are presented. The measurements showed that the magnetic properties of some of the weights were over the limits for weights of their classes [1]. These magnetic forces which cannot be corrected may give false balance readings during a mass measurement.