可调光程柱面多通池TDLAS系统

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Abstract： In order to improve the detection performance and integration of TDLAS detection system，A TDLAS system based on a portable adjustable optical path length cylindrical miror multi-passcell was designed，which achieved the simulated optical path length of 14m ， 10.6m ， 9.2m ， 7.1m and 5.8m .To reduce the impact of noise generated during gas measurement in TDLAS system on detection accuracy and sensitivity，the Variational Mode Decomposition（VMD）wavelet denoising algorithm optimized by the Northern Goshawk Optimization （NGO） was proposed. The simulation results showed that compared with other algorithms，the NGO-VMD wavelet denoising algorithm could effectively reduce noise without causing signal distortion. The performance of the system was evaluated by testing CH4 using a DFB laser with the central wavelength of 1.653μm based on direct absorption detection technology. The results showed that the signal-to-noise ratio of the detection signal was increased from 66 to 1O9，and the lower detection limit of the system was improved from 12.1ppm to 7.28ppm . Allan analysis of variance showed that the optimal detection sensitivity of the system was improved from 641ppb to 526ppb at the integra tion time of 263 s after optimization with the NGO-VMD wavelet algorithm. The finding provided a refer ence for improving the performance of TDLAS trace gas detection system.

Key Words： Tunable Diode Laser Absorption Spectroscopy（TDLAS）； direct absorption； adjustable optical path length； northern goshawk optimization algorithm; variational mode decomposition

1引言

可调谐二极管激光吸收光谱技术（TunableDiode Laser Absorption Spectroscopy，TDLAS）因其响应速度快、检测灵敏度高、选择性好、易于小型化等特点在痕量气体检测，气体泄漏警报等[1-4]方面得到广泛的应用。（剩余15290字）