A Servo-Controlled Balance for the Absolute Ampere Determination
Hisao Nakamura · Japanese Journal of Applied Physics · 1978
A servo-controlled balance for the absolute ampere determination has been developed. The force can be measured with high speed (in a few minutes) and with high sensitivity (10 -8 N). The analysis of the current balance also agrees with the experiments. The noise by the convection current of air produced by heating in the moving coil is newly estimated. The current of the moving coil for obtaining the best signal to noise ratio is around 1 A in the present coil system.