Assessment of torque in clip-round moving-iron meters

The methods of torque assessment described in the paper were developed in the course of a programme for increasing the sensitivity of a particular type of clip-round moving-iron instrument. The principal method exploits the relation between inductance change and torque, and so avoids the necessity for constructing precise bearings during the innovating programme. Measurements to simulate the effect of the earth´s field are also presented and conclusions are reached concerning the limitations of sensitivity of this type of instrument.