Study on Differential Optical Absorption Spectroscopy Data Processing Based on Discrete Spectrum Correction
JIA Gui-hong1,2,ZHANG Jian-jun2,ZHENG Hai-ming2
1. School of Mechanical Engineering, Hebei University of Technology, Tianjin 300130, China
2. School of Energy Power and Mechanical Engineering, North China Electric Power University, Baoding, Hebei 071003, China
Abstract：The Fourier transform filtering method is used to filter out the noise in the differential optical absorption spectrum (DOAS) data. Due to the limitation of frequency resolution, the amplitude error is large, which affects the detection accuracy of gas. A method that discrete spectrum correction differential optical absorption spectrum data method is proposed, which uses the barycenter of the spectral line in the main lobe of the discrete spectrum to find the coordinate of the peak, and compensates the amplitude error to improve the measurement accuracy of gas. Many groups of SO2 gases with different concentrations are measured. The results show that the inversion error of the spectrum correction method is less than 5%, and compared with the traditional least square method and the Fourier transform filtering method, the error is reduced by 0.36% and 0.88% respectively. When the spectral lines are shifted by 2 sampling intervals 0.28nm, the average error of the traditional least square method is 31.8%, and the maximum error of the spectrum correction method is 3.8%. The latter is obviously superior to the former.
［1］Wang L, Zhang Y G, Zhou X, et al. Optical sulfur dio-xide sensor based on broadband absorption spectroscopy in the wavelength range of 198–222nm ［J］. Sensors & Actuators, B. Chemical, 2017, 241 (3): 146-150.
［2］Al-Jalal A, Al-Basheer W, Gasml K, et al. Measurement of low concentrations of NO2 gas by differential optical absorption spectroscopy method ［J］. Measurement, 2019, 146: 613-617.
［3］郑海明, 刘佳. 差分吸收光谱测量臭氧浓度信号去噪的实验研究 ［J］. 计量学报, 2020, 41 (6): 759-764.
Zheng H M, Liu J. Experimental study on denoising of ozone concentration signal by differential absorption spec-troscopy ［J］. Acta Metrologica Sinica, 2020, 41 (6): 759-764.
［4］刘前林, 王立世, 黄新建, 等.傅里叶变换在差分吸收光谱技术气体浓度计算中的应用 ［J］. 光谱学与光谱分析, 2008, 28 (12): 2830-2834.
Liu Q L, Wang L S, Huang X J, et al. Using Fourier transform to calculate gas concentration in DOAS ［J］. Spectroscopy and Analysis, 2008, 28 (12): 2830-2834.
［5］Zhang X X, Xiao H Y, Li X, et al. Ultraviolet differ-ential spectroscopy quantitative analysis of SF6 decompo-sition component SO2 ［J］. IET Science Measurement & Technology, 2018, 12 (3): 328-334.
［6］周红, 肖淞, 张晓星,等.基于紫外差分吸收光谱的痕量SO2气体定量检测 ［J］. 中国电机工程学报, 2017, 37 (19): 5812-5820, 5859.
Zhou H, Xiao S, Zhang X X, et al. Quantum Detection of Trace Sulfur Dioxide Based on Ultraviolet Differential Optical Absorption Spectrometry ［J］. Proceedings of the CSEE, 2017, 37 (19): 5812-5820, 5859.
［7］Zheng H M , Yao P H. Study on Ozone concentration based on the Fourier transform-differential absorption spectrum method ［J］. Ozone: Science & Engineering, 2016, 38 (5): 52-357.
［8］王宁, 龚天诚, 陈建君等. 新型傅里叶变换光谱探测系统相位误差校正方法 ［J］. 光谱学与光谱分析, 2014, 34 (11): 2934-2937.
Wang N , Gong T C , Chen J J, et al. A Phase Error Correction Method for the New Fourier Transforms Spectrometer ［J］. Spectroscopy and Spectral Analysis, 2014, 34 (11): 2934-2937.
［9］郑海明, 李广杰, 吴浩. 基于线性调频Z变换的差分吸收光谱数据处理方法研究 ［J］. 光谱学与光谱分析 ［J］. 2015, 35 (6): 1633-1638.
Zheng H M, Li G J, Wu H. Study on Differential Optical Absorption Spectroscopy Data Processing Based on Chirpz-Z Transformation ［J］. Chinese Journal of Lasers, 2015, 35(6): 1633-1638.
［10］郁敏捷, 刘铭晖, 董作人, 等. 基于傅里叶变换的差分吸收光谱法测量NH3和SO2浓度的实验研究 ［J］. 中国激光, 2015, 42 (9): 351-359.
Yu M J, Liu M H, Dong Z R, et al. Study on measuring concentration of ammonia and sulphur dioxide by differential optical absorption spectrometry based on fast Fourier transform ［J］. Chinese Journal of Lasers, 2015, 42 (9): 351-359.
［11］Liu Z L, Sun L Q, Guo Y, et al. The calibration research of DOAS based on spectral optical density［J］. Spectroscopy and spectral analysis, 2017, 37 (4): 1302-1306.
［12］Cui Z L, Zhang X X, Cheng Z, et al. Quantitative analysis of SO2, H2S and CS2 mixed gases based on ultraviolet differential absorption spectrometry［J］. Spectrochimica acta part A-molecular and Bio Molecular Spectroscopy, 2019, 215:187-195.
［13］郑海明, 李长朝. 基于高温还原及差分吸收光谱监测烟气汞的实验研究 ［J］. 计量学报, 2017, 38 (6): 780-785.
Zheng H M, Li C Z. Research on Flue Gas Mercury Based on High Temperature Reduction ［J］. Acta Me-trologica Sinica, 2017, 38 (6): 780-785.
［14］王志芳, 王书涛, 王贵川, 等. 基于小波优化EEMD的二氧化硫检测 ［J］. 计量学报, 2020, 41 (6): 752-758.
Wang Z F, Wang S T, Wang G C, et al. Detection of SO2 based on EEMD optimized by wavelet ［J］. Acta Metrologica Sinica, 2020, 41 (6): 752-758.
［15］Luo J F, Xie Z J, Mie M. Generalization of interp-olation DFT algorithms and frequency estimators with high image component interference rejection ［J］. Jour-nal on Advances in Signal Processing, 2016, 2016 (1): 1-11.
［16］Lin H B, Ding K. Energy based signal parameter esti-mation method and a comparative study of different fre-quency estimators ［J］. Mechanical Systems and Signal Processing, 2011, 25 (1): 452-464.
［17］丁康, 江利旗. 离散频谱的能量重心校正法 ［J］. 振动工程学报, 2001(3): 110-114.
Ding K, Jiang L Q. Energy Centro baric correction method for discrete spectrum ［J］. Journal of Vibration Engineering, 2001 (3): 110-114.
2021, Vol. 42 
