Novel method used for phase lock voltage subtraction of micro water vapor detection

Abstract

The invention provides a novel method used for phase lock voltage subtraction of micro water vapor detection, and belongs to the technical field of optical fiber sensing detection. Wavelength modulation is conducted on a laser, and signals passing through gas-absorption peaks and non-absorption positions are detected through the phase locking technology and are processed. An achieving system comprises a temperature controlling and driving module of the laser, the laser, a one-to-one optical fiber coupler, a gas chamber, a photoelectricity detector, a current and voltage conversion module, an automatic gain control amplifier, a subtracter, a phase locking module and a signal processing and detecting module. According to the novel method, as the phase locking module is used and detection signal subtraction is conducted before phase locking, the signal to noise ratio can be greatly improved, and gas concentration signals are effectively extracted. Automatic gain amplification can overcome the detect that vibration of optical fibers, power fluctuation of the laser and other factors cause light intensity signal changes, and stability of the system can be improved. In addition, the system has the advantages of being small in size, simple in structure, low in cost and the like.

Description

technical field [0001] The invention relates to a new phase-locked voltage subtraction method for trace water vapor detection, which is a new method for trace water vapor detection by simultaneously using voltage subtraction, phase-locked and self-gain control technologies. Belongs to the field of optical fiber sensing detection technology Background technique [0002] Detection of water vapor concentration is of great significance in many fields. The existence of water in natural gas will cause pipeline water blockage, cause pipeline ice blockage, corrode pipelines, equipment and instruments, affect the accuracy of natural gas metering, and cause great harm to the safe production and use of natural gas. The more water content in transformer oil, the faster the aging of the oil itself, the aging of equipment insulation and the corrosion of metal parts, so it is very necessary to monitor the water content in the oil. In electrical equipment such as high-voltage switches, SF...

AI Technical Summary

Problems solved by technology

This method can greatly improve the signal-to-noise ratio, but because there is water in the production process of photodetectors and lasers and they are easily affected by the concentration of water vapor in the outside atmosphere, and the vibration of optical fibers and fluctuations in laser power will affect the light intensity. It has an impact on water vapor detection, so the detection accuracy is limited

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