All-fiber open type gas monitoring system and detection method

Abstract

The invention discloses an all-fiber open type gas monitoring system and a detection method. The system comprises a wavelength tunable laser, an optical fiber coupler, an optical fiber beam splitter,an optical fiber collimator, a reference pool based on a hollow-core optical fiber, an optical fiber ring cavity interferometer, a three-mirror cavity system, a focusing lens, a photoelectric detector, a laser control module, an analog-to-digital conversion module, a digital-to-analog conversion module and a computer control unit. According to the invention, the hollow-core optical fiber and the optical fiber ring cavity interferometer which are small in size and high in flexibility are used for replacing a traditional fragile glass type absorption cell and an F-P type etalon sensitive to an optical path respectively to realize laser center frequency locking, spectral system correction and tuning frequency range correction; the three-mirror cavity system is used for replacing a traditionaltwo-mirror linear reflection mode to achieve large-range area open type gas monitoring.

Description

technical field [0001] The invention relates to the technical field of laser spectrum and optical fiber sensing, in particular to an all-fiber type open gas monitoring system and a detection method. Background technique [0002] There are many toxic, harmful, flammable and explosive gases in the production and living environment of modern society, which pose potential hazards to personnel health and safety. In some open places, such as industrial parks, chemical plants, oil and gas storage stations, and other areas where there is no combustion and no fire, it is necessary to monitor and warn of certain harmful gases and hazardous chemicals. However, the traditional offline gas sampling back to the laboratory analysis method is far from meeting the needs of real-time monitoring, so real-time online remote sensing gas monitoring has become the only effective means. [0003] Under the existing technical conditions, the open monitoring of trace gas is mainly realized by Fourier...

AI Technical Summary

Problems solved by technology

Among them, although the Fourier transform infrared spectrometer can measure multiple components at the same time, it has the following problems: First, in order to obtain higher sensitivity, the detector part needs to be cooled by liquid nitrogen, resulting in expensive and bulky Bulky and inconvenient to carry

Second, it takes a long time to perform spectral scanning and data calculation, which leads to the problem of slow data processing speed

The open infrared gas sensor based on TDLAS technology is mainly based on two cavity mirrors, which can only achieve linear distance measurement. Usually, it is necessary to integrate a glass reference cell and an air-gap F-P etalon for laser center frequency locking and frequency correction. Realize the inversion of gas concentration, which leads to the problems of cumbersome system structure and limited monitoring range

Therefore, it is important to develop a new trace gas monitoring system to solve the problems of the existing trace gas monitoring system, such as high cost, bulky, inconvenient to carry, slow data processing speed, cumbersome structure, and short monitoring distance. Scientific Significance and Application Value

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