Magnetic Field Measurement in Beta-Spectroscopy

Abstract

To measure precisely the instantaneous value of a magnetic field, a device consisting of a drum-armature wound on a Lucite form and rotated by a synchronous motor is described. The direct voltage output is taken off by commutator and brushes, both of silver, to a potentiometer. Changes of 0.01 gauss can be observed. A simple self-regulating circuit is described.