METHOD FOR COMPENSATING FIBRE-OPTIC MEASURING SYSTEMS AND FIBRE-OPTIC MEASURING SYSTEM

摘要

The invention relates to a method for compensating, e.g. for compensating the temperature of a fibre-optic measuring system designed to detect a mechanical variable. First and second fibre Bragg gratings have a respective Bragg wavelength and the fibre Bragg gratings are irradiated with primary light. After the mechanical variable is applied to the first and second fibre Bragg gratings, the Bragg wavelengths of the fibre Bragg gratings are modified by the mechanical variable. The first and second secondary light that has been produced by the primary light and modified by the Bragg wavelength of the fibre Bragg grating in conjunction with the mechanical variable is filtered by means of an optical filter device, in such a way that the Bragg wavelength of the first fibre Bragg grating lies in the region of the rising filter edge and the Bragg wavelength of the second fibre Bragg grating lies in the region of the falling filter edge of the optical filter device. Once the intensities of the filtered first and second secondary light have been detected, said intensities are compared, as a result of which the mechanical variable can be determined from said intensity comparison.