Fibre optic magnetic sensor

摘要

A fibre optic magnetic sensor is disclosed. The sensor has a thin-walled cylindrical barrel with a mid-section which is elastically radially deformable. A single mode optical fibre is wound about the mid section of the barrel. A magnetostrictive element is located within the center of the barrel and secured to both ends of the barrel. Changes in the external magnetic field in the vicinity of the sensor cause changes in the length of the magnetostrictive element and consequently cause axial forces to be applied to the end of the barrel. The mid-portion of the barrel deforms radially, thus inducing a strain in the optical fibre from which the external magnetic field strength may be deduced.