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 conductors (1) influence 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). A reflecting surface (5) is provided at one end (4) of the optical fibre (2) and the light enters and leaves at the other end (6). In order to exploit the advantages of the twisting of the optical fibre while reducing all other measurement errors, circular double refraction is conferred in a known manner on the optical fibre (2) by twisting it about its longitudinal axis, and the end (4) of the optical fibre (2) with the reflecting surface is arranged in the immediate vicinity of the other end (6) so that the whole optical fibre (2) forms an almost completely closed loop.