Patent ID: 8405391

Claim:
A sensor comprising: a magnetic field source, at least one flux conducting soft magnetic element magnetically coupled to said magnetic field source; at least one air gap in the flux conducting soft magnetic element; at least one magnetic field sensor located in the air gap and adapted to measure a change of the magnetic field of the magnetic field source, wherein the at least one flux conducting soft magnetic element comprises an alloy that consists of: Ni, such that 35% by weight≦Ni≦45% by weight, Co, such that 0% by weight≦Co≦2% by weight, Mn, such that 0% by weight≦Mn≦1.0% by weight, Si, such that 0% by weight≦Si≦0.5% by weight, and Cr or Mo, or both, such that 0.5% by weight≦Cr≦6.65% by weight and/or 0.5% by weight≦Mo≦8% by weight, wherein (Mo+Cr)≦8% by weight, rest iron and unavoidable impurities.