An educational Kohlrausch ammeter

摘要

The Kohlrausch ammeter is based on the measurement of the force actingbetween a solenoid and a soft iron rod inserted inside it. In this article, wepresent a new version of the instrument for educational purposes: in ourdevice the dynamometer, which is usually employed to measure the force, isreplaced by an electronic balance. The operation of the instrument issatisfactory: the precision is better than 1%. Furthermore, the measurementscan be useful to improve students' knowledge of magnetism and magneticmaterials.