A design is herein given for an electromagnetic device that can be employed instead of weights or springs for weighing purposes. In this particular design the balancing current is linear with the force applied to the arm of the balance so that current measurement gives a direct reading of weight. A capacity null‐point indicator is also described and so also are electrical circuits that enable this null‐point indicator to automatically operate the electromagnet. These auxiliaries are shown incorporated in a density balance. This balance was sensitive to a change of weight of better than 0.0000001 gram or in terms of oxygen pressure at room temperature to 0.02 mm of Hg. The designs of density balances are discussed.