A precision form of the Kelvin electrostatic voltmeter

The paper describes a form of electrostatic voltmeter for precision measurements. The instrument follows the general arrangement of the Kelvin type. The chief modifications are : (1) Very considerable reduction in weight, permitting (2) the use of a bifilar suspension to overcome the effect of elastic fatigue: (3) a modification of the shape of the needle to produce a more satisfactory ¿scale law¿ for both small and large deflections: and (4) the provision of various mechanical details to facilitate construction and adjustment