FIBER-OPTIC SENSOR OF MAGNETIC FIELD AND ELECTRIC CURRENT Russian patent published in 2021 - IPC G01R29/00 

FIELD: monitoring and measuring equipment.

SUBSTANCE: invention relates to control and measurement equipment and can be used for measurement of magnetic field and electric current in power engineering and other fields. Disclosed fiber-optic sensor of magnetic field and electric current comprises a magnetooptical unit and a processing unit connected by optical fibers. Magnetooptical unit includes input and output light guides, a collimating lens, a polariser, a circular bipolar breaker made in the form of a magnetically sensitive film, a focusing lens and a differential polarization analyzer. Processing unit includes a radiation source associated with the input optical waveguide of the magnetooptical unit, two photodetectors connected at the input to output light guides of the magnetooptical unit, and on the output to the differential signal generating device. Polariser and the differential polarization analyzer are made from a birefringing crystal, the optical axis of polariser is 45° with direction of radiation, and the plane containing the optical axis of the differential polarization analyzer and the radiation direction is 45° with similar plane of polariser. Length of the differential polarization analyzer ensures spreading of ordinary and extraordinary beams by not less than the diameter of the output light guide, and processing device includes a device for generating summation signals and a rating device connected to outputs of devices for generating summation and difference signals.

EFFECT: higher accuracy and stability of measurements during long service life in operating conditions with minimum dimensions and cost of equipment.

1 cl, 2 dwg