Reduction of magnetic-field fluctuations by an inductive feedback system
M. Abignoli · Electronics Letters · 1965
A sensing coil is used to detect the magnetic-field fluctuation, and a pair of Helmholtz coils is used to create an opposing field to reduce this fluctuation to a minimum. The Helmholtz-field inhomogeneity in the sensing-coil area sets a limit to the accuracy of the experiment.