Patent ID: 7131339

Claim:
A method for measuring dynamic torques in a rotating shaft, the method comprising the steps of: (a) affixing a ferromagnetic strip circumferentially around a portion of said shaft while said shaft is stationary; (b) moving a permanent magnet having circumferentially aligned poles around said ferromagnetic strip to establish a baseline circumferential magnetic field within said ferromagnetic strip; (c) positioning a magnetostrictive detection coil in spaced proximity to said rotating shaft adjacent said ferromagnetic strip, said detection coil having an induced voltage therein indicative of a magnetic flux change within said ferromagnetic strip on said rotating shaft; (d) receiving, amplifying, and filtering a signal from said detection coil; and (e) analyzing said signal and determining a quantitative value for said dynamic torques, wherein said dynamic torques generate said magnetic flux changes within said ferromagnetic strip detectable by said detection coil.