High Sensitivity Methane Detection System Based on Double Spherical Mirror Multi-pass Cell
-
摘要:
为了准确测量环境大气中的痕量气体甲烷浓度，采用可调谐二极管激光吸收光谱（TDLAS）技术，选取中心波长为1653 nm的分布反馈式（DFB）激光器作为激光光源，搭建甲烷检测系统。针对系统中的探测器噪声与光学干涉条纹噪声，利用加入射频噪声源、多次平均以及卡尔曼（Kalman）滤波方法，来提高系统检测精度。实验结果表明：结合长光程多通池和TDLAS技术对甲烷浓度进行检测，标定的甲烷浓度与系统检测的二次谐波信号峰值有良好的线性关系；当积分时间为213 s时，Kalman滤波后系统的最低检测限为0.14 ppb；确定加入射频噪声源的最优参数，比较多次平均以及利用Kalman滤波进行数据处理，在平均时间为10 s时测量精度为144 ppb，而经过Kalman滤波后测量精度达到134 ppb，表明Kalman滤波可以实现较高的测量精度。
Abstract:To accurately measure the concentration of trace gas methane (CH4) in ambient atmosphere, tunable diode laser absorption spectroscopy (TDLAS) technology was adopted, and a distributed feedback (DFB) laser with a central wavelength of 1653 nm was selected as the laser light source to build a CH4 detection system. For the detector noise and optical interference fringe noise in the system, radio frequency (RF) noise source, multiple averaging, and Kalman filtering were added to improve the detection accuracy of the system. The experimental results show that the calibrated CH4 concentration has an ideal linear relationship with the peak value of the second harmonic signal detected by the system by combining the long optical path multi-pass cell (MPC) and TDLAS technology. The minimum detection limit of the Kalman filtered system is 0.14 ppb when the integration time is 213 s. By determining the optimal parameters for adding RF noise sources and comparing multiple averaging techniques, a measurement accuracy of 144 ppb at an averaging time of 10 s was achieved. After applying Kalman filtering for data processing, the measurement accuracy reached 134 ppb, indicating that Kalman filtering can achieve high measurement accuracy.
-
Keywords:
- TDLAS technology /
- MPC /
- CH4 detection /
- Kalman filtering /
- minimum detection limit
-
-
![]()
图 2 目标气体CH4及干扰分子CO2、H2O的光吸收谱线
Figure 2. Optical absorption lines of target gas CH4 and interfering molecules CO2 and H2O
![]()
图 4 多通池结构
注：1-窗片；2-密封圈；3-镜片固定圆环；4-入射孔、出射孔；5-窗片盖；6-底座1；7-换气孔；8-石英玻璃管；9-上压板；10-镜片压板；11-底座2
Figure 4. Structure diagram of MPC
Note: 1-Window piece; 2-Seal ring; 3-Lens fixing ring; 4-Inlet hole and outlet hole; 5-Window cover; 6-Base 1; 7-Gas exchange hole; 8-Quartz glass tube; 9-Upper plate; 10-Lens platen; 11-Base 2
![]()
图 7 二次谐波信号峰值与浓度的关系
Figure 7. Relations between peak value and concentration of second harmonic signal
![]()
图 8 反演与滤波、系统Allan方差曲线及浓度分布直方图
Figure 8. Inversion and filtering, system Allan variance curve and concentration distribution histogram
![]()
图 9 二次谐波信号的信噪比和标准偏差随噪声大小的变化
Figure 9. Variation of signal-to-noise ratio and standard deviation of second harmonic signal with noise
-
[1] ZHOU X, LIU P, ZHOU X. Generalized design of simple, stable and compact nested multipass cells with a reentrant symmetric concentric circle pattern[J]. Optics Express, 2023, 31(3): 4152-4163. DOI: 10.1364/OE.479762
[2] XIA J, FENG C, ZHU F, et al. A sensitive methane sensor of a ppt detection level using a mid-infrared interband cascade laser and a long-path multipass cell[J]. Sensors and Actuators B: Chemical, 2021, 334(30): 1-8. http://www.sciencedirect.com/science/article/pii/S0925400521002094
[3] 田兴, 朱乐文, 李龙, 等. 基于射频噪声源下的离轴积分腔输出光谱技术中腔镜反射率标定研究[J]. 大气与环境光学学报, 2023, 18(5): 494-502. TIAN Xing, ZHU Lewen, LI Long, et al. Study on reflectivity calibration of cavity mirror in off-axis integrated cavity output spectrum technology based on RF noise source [J]. Journal of Atmospheric and Environmental Optics, 2023, 18(5): 494-502.
[4] 赵成龙, 黄丹飞, 刘智颖, 等. 开放型TDLAS-WMS技术CO2痕量气体检测[J]. 光子学报, 2022, 51(2): 333-342. ZHAO Chenglong, HUANG Danfei, LIU Zhiying, et al. Open TDLAS-WMS technology for CO2 trace gas detection[J]. Acta Photonica, 2022, 51(2): 333-342.
[5] 冯仕凌, 崔琪, 郭心骞, 等. 小波降噪对TDLAS干涉抑制的研究[J]. 大气与环境光学学报, 2022, 17(3): 328-335. FENG Shiling, CUI Qi, GUO Xinqian, et al. Study on interference suppression of TDLAS by wavelet denoising [J]. Journal of Atmospheric and Environmental Optics, 2022, 17(3): 328-335.
[6] 梁承权, 吕德深, 朱浩亮, 等. 基于TDLAS技术与小波变换去噪算法的甲烷浓度检测[J]. 红外技术, 2023, 45(2): 209-216. http://hwjs.nvir.cn/article/id/7d1d155c-19dc-4999-8757-99bca5fc0240 LIANG Chengquan, LV Deshen, ZHU Haoliang, et al. Methane concentration detection based on TDLAS technology and wavelet transform denoising algorithm[J]. Infrared technology, 2023, 45(2): 209-216. http://hwjs.nvir.cn/article/id/7d1d155c-19dc-4999-8757-99bca5fc0240
[7] 李恒宽, 朴亨, 王鹏, 等. 基于近红外吸收光谱技术的高精度CO2检测系统的研制[J]. 红外与激光工程, 2023, 52(3): 115-121. LI Hengkuan, PARK Heng, WANG PANG, et al. Development of high-precision CO2 detection system based on near infrared absorption spectroscopy[J]. Infrared and Laser Engineering, 2023, 52(3): 115-121.
[8] 李金义, 杨雪, 张宸阁, 等. 参数优化的Kalman滤波用于激光吸收光谱气体测量[J]. 光学学报, 2022, 42(18): 207-214. LI Jinyi, YANG Xue, ZHANG Chenge, et al. Parameter-optimized Kalman filter for gas measurement in laser absorption spectrum[J]. Acta Optica Sinica, 2022, 42(18): 207-214.
[9] CAO Y, MA Y, CHENG X, et al. Parameter-tuning stochastic resonance as a tool to enhance wavelength modulation spectroscopy using a dense overlapped spot pattern multi-pass cell[J]. Opt Express, 2022, 30(18): 32010-32018. DOI: 10.1364/OE.465629
[10] 梁宇, 刘铁根, 刘琨, 等. 基于变分模态分解算法的气体检测优化方法[J]. 中国激光, 2021, 48(7): 135-144. LIANG Yu, LIU Tiegen, LIU Kun, et al. Optimization method of gas detection based on variational modal decomposition algorithm [J]. China Laser, 2021, 48(7): 135-144.
[11] 鲁一冰, 刘文清, 张玉钧, 等. 一种自适应层进式Savitzky -Golay光谱滤波算法及其应用[J]. 光谱学与光谱分析, 2019, 39(9): 2657-2663. LU Yibing, LIU Wenqing, ZHANG Yujun, et al. An adaptive hierarchical Savitzky-Golay spectral filtering algorithm and its application[J]. Spectroscopy and Spectral Analysis, 2019, 39(9): 2657-2663.
-
期刊类型引用(3)
1. MENG Yinjie，WEI Zhengjun，YAN Ziling，WANG Jindong. Development of a bias power supply for Geiger mode avalanche photodiodes. Optoelectronics Letters. 2023(11): 659-665 . 
必应学术
2. 陈良洲，鲁猛，陈有林. 基于TPS61175的BOOST升压及电荷泵倍压电路设计. 电子设计工程. 2021(11): 189-193 . 百度学术
3. 刘智恒. 光电二极管在物理中的应用. 家庭生活指南. 2018(09): 70 . 百度学术
其他类型引用(3)
下载:
计量
- 文章访问数: 26
- HTML全文浏览量: 5
- PDF下载量: 14
- 被引次数: 6
