Method for compensation of fiber optic measurement systems and fiber optic measurement system

摘要

The present invention relates to a method for compensation, for example, for temperature compensation of a fiber optic measurement system designed for determining a mechanical quantity. First and second fiber Bragg gratings have a respective Bragg wavelength, wherein the fiber Bragg gratings are irradiated with primary light. After applying a mechanical quantity to the first and second fiber Bragg gratings, the Bragg wavelengths of the fiber Bragg gratings are changed by the mechanical quantity. Filtering of the first and second secondary light, said first and second secondary light is effected from the primary light and modified by the Bragg wavelength of the fiber Bragg grating depending on the mechanical quantity by use of an optical filter device follows, in such a way that the Bragg wavelength of the first fiber Bragg grating lies in the region of the rising filter gradient of the optical filter device and the Bragg wavelength of the second fiber Bragg grating lies in the region of the falling filter gradient of the optical filter device. After determining the intensities of the filtered first and second secondary light, they are compared, whereupon the mechanical quantity is determined from the intensity comparison.

主权项

1. Method for compensating a fiber optic measurement system designed to determine a mechanical quantity, comprising:
providing, in the fiber optic measuring system, a first and at least a second fiber Bragg grating, which have a respective Bragg wavelength; irradiating the fiber Bragg grating with primary light; application to the first and second fiber Bragg grating of the mechanical quantity in such a way that the Bragg wavelength of the fiber Bragg grating is changed by the mechanical quantity, wherein the first and at least second fiber Bragg gratings are affected substantially equally by a disturbance quantity A and affected differently by the mechanical quantity; filtering the first and second secondary light, said first and second secondary light is effected from the primary light and modified by the Bragg wavelength of the fiber Bragg grating depending on the mechanical quantity, by use of an optical filter device with a rising and a falling filter gradient, wherein the Bragg wavelength of the first fiber Bragg grating, in a state in which the first fiber Bragg grating is unaffected by the mechanical quantity, lies in a range of the rising filter gradient of the optical filter device and the Bragg wavelength of the second fiber Bragg grating, in a state in which the second fiber Bragg grating is unaffected by the mechanical quantity, lies in a range of the falling filter gradient of the optical filter device; determining the intensities of the filtered first and second secondary light; evaluating the determined intensities of the filtered first and second secondary light, wherein the evaluation of the determined intensities of the filtered first and second secondary light comprises a summation of the intensity of the first secondary light and the intensity of the second secondary light; and determining the mechanical quantity from the intensity evaluation.