Wiegand wire - with alternating ferro and paramagnetic lengths produced by direct current passage and cuffs

摘要

A WIEGAND wire, made of 37% Fe, 52% Co and 11% V, produces in its ferromagnetic state in an alternating field the so-called Barkhausen jumps. For use as displacement pickups, the wire should have a sequence of ferromagnetic with paramagnetic zones which exhibit no such jumps. This is best achieved by heating the wire in the paramagnetic zones to a dark red heat by passing a current of high density through them. The ferromagnetic zones are kept cool by applying heat dissipating cuffs.