Automatic calibration circuit and calibration method for fiber grating demodulator F-P filter

Abstract

The invention discloses an automatic calibration circuit for a fiber grating demodulator F-P filter. A CPU controls the output voltage of a first DA converter to reach a starting voltage; the output voltage of a second DA converter serves as a reference voltage of a third DA converter; adjustable range of the output voltage of the third DA converter is realized by adjusting the output voltage of the second DA converter; and a voltage adder enables the starting voltage and a scanning voltage to be superposed, and then, through phase inversion of a voltage phase inverter, the voltage drives the F-P filter. The invention further discloses an automatic calibration method for the fiber grating demodulator F-P filter. The method is characterized by, in the operation process, calculating a center voltage V3 of the first peak and a center voltage V4 of the last peak of an etalon after each scanning measurement; and controlling the range V1-V2 of the output voltage Vo of the voltage adder to be from V3-1.5 V to V4+1.5 V. The method can determine the voltage scanning range of the F-P filter automatically, thereby saving time and labor.

Description

technical field [0001] The invention relates to an automatic calibration circuit for an F-P filter of an optical fiber grating demodulator, and also relates to an automatic calibration method for an F-P filter of an optical fiber grating demodulator, belonging to the technical field. Background technique [0002] As a new generation of sensors, fiber optic sensors can measure many physical quantities, chemical quantities and biomass with high resolution, and can realize the measurement of on-site non-electrical measurements, which essentially solves the problem of flammability and flammability that traditional electrical sensors are difficult to get involved in. It can detect the safety measurement of explosive and strong electromagnetic field places; it can conveniently, accurately and effectively detect the relevant physical quantities, chemical quantities and biomass in various environments, especially in various harsh environments. In addition, the optical fiber has a la...

AI Technical Summary

Problems solved by technology

[0006] (1) The scanning voltage needs to be adjusted manually

[0007] Since the scanning voltage range of each F-P filter corresponding to the wavelength between 1525 and 1565nm is not fixed, the driving voltage range of the F-P filter is currently adjusted manually, which is extremely time-consuming and laborious.

[0008] (2) F-P filter is greatly affected by temperature

[0009] At different temperatures, the scanning voltage range of each F-P filter corresponding to the wavelength between 1525 and 1565nm is not fixed. It is necessary to determine the scanning voltage range of the F-P filter at high and low temperature respectively, and take the scanning voltage at high and low temperature The union of the range, so as to meet the normal measurement at high temperature, which will greatly reduce the resolution of the measurement, and the whole calibration process consumes a lot of manpower

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