| 摘要 |
In a fibre optic arrangement for measuring the strength of an electric current using the Faraday effect, the magnetic field surrounding the current-carrying conductor (1) influences the polarization condition of the light which travels through the core of an optical fibre (2) surrounding the conductor (1) in the form of a winding (3). The light which emerges from the optical fibre (2) is split by a beam splitter (9) into two partial light beams each of which passes through a polarizer (12, 11). The intensity (I1, I2) of each partial light beam is then measured by a photodetector (14, 13). In order to extend the measurement range of the arrangement, the polarizers (12, 11) are rotated symmetrically to each other through an angle other than the conventional angle of 45 DEG . The angle ( alpha ) between the polarizers (12, 11) and the polarization plane of the light entering the optical fibre (2) lies between +20 DEG and +40 DEG and -20 DEG and -40 DEG , respectively. |
