Patent ID: 8578794

Claim:
A method for reducing the noise in a signal from a torque sensor caused by near magnetic field sources, the method comprising the steps of: providing a torque sensor comprising: a longitudinally extending member; a magnetoelastically active region directly or indirectly attached to or forming a part of the surface of the member in such a manner that torque applied to the member is proportionally transmitted to the active region, the active region comprising at least one region magnetically polarized such that the magnetized polarity becomes increasingly helically shaped as the applied torque increases; at least one primary magnetic field sensor arranged proximate the at least one region for outputting a first signal corresponding to a torque-dependent magnetic flux emanating from the active region; at least one secondary magnetic field sensor axially spaced in a first direction by a pre-determined first distance from the at least one primary magnetic field sensor for outputting a second signal corresponding to an ambient magnetic flux emanating from a near magnetic field source; at least one secondary magnetic field sensor axially spaced in a second direction opposite the first direction a pre-determined second distance from the at least one primary magnetic field sensor for outputting a third signal corresponding to the ambient magnetic flux emanating from the near magnetic field source; receiving the first signal upon application of the torque; receiving the second and third signals; and adjusting the first signal using the second and third signals thereby compensating for effects of the near magnetic field source.