| 摘要 |
A three-dimensional magnetic field sensing arrangement comprises three magnetic non-conducting sensors, e.g. 1a, arranged for sensing the three respective components of an external magnetic field. Each sensor comprises a sensor module 2, a transmitter module 3 containing a laser diode 13, and a receiver module 4 containing a photodetector 14 and a filter and amplifier 15. The sensor module 2 comprises in sequence a collimating lens 5, connected to an efferent optic fibre 6, a first polarising beam-splitter 7, a half-wave plate 8, a rare-earth-doped iron garnet Faraday-effect transducer 9, which rotates the plane of polarisation of the light through an angle which depends on the component of an external magnetic field in the propagation direction, a second polarising beam-splitter 10 and a focussing lens 11 connected to an afferent optic fibre 12. The invention finds particular application in measuring magnetic fields associated with electrical breakdown in high-voltage environments, for which sensors made from conductive materials are not suitable, as well as measuring any type of magnetic fields in environments with high electric fields and high voltages. |
