摘要
针对波长调制光谱技术中二次谐波背景信号漂移的问题,将背景信号历史数据中与实测二次谐波信号相似的信号作为背景信号,提出了一种气体体积分数反演方法。首先,选用中心波长在5.18μm附近的激光器,搭建了NO体积分数测量系统,并将48 h内测量的纯N2背景信号作为历史数据构建背景信号库。然后,在系统中通入NO,得到经过吸收的二次谐波信号并计算其与背景信号库中各背景信号的相关系数。最后,扣除最大相关系数下的背景信号后反演气体的体积分数。对体积分数为2.5×10^(-6)的NO进行了24 h的监测,结果表明,该方法可将平均相对误差从修正前的6.48%提高到3.84%。
In this study,a gas volume fraction-inversion method is proposed to solve the drifting issue of the second harmonic background signal in the wavelength modulation spectroscopy technology.Here,the signal similar to the measured second harmonic signal in the background signal history data is taken as the background signal.First,a laser with a central wavelength of ~5.18μm is used to build a NO volume fraction measurement system and a background signal library is constructed using the pure N2 background signal measured within 48 h as historical data.Subsequently,the NO is passed into the system,and the absorbed second harmonic signal and the correlation coefficient between it and each background signal in the background signal library is calculated.Finally,the volume fraction of the gas is retrieved after subtracting the background signal from the maximum correlation coefficient.The NO with a volume fraction of 2.5×10^(−6) is monitored for 24 h,and the results show that the method could decrease the average relative error from 6.48% before correction to 3.84%.
作者
张敏
方健
王勇
莫文雄
郝方舟
杨帆
林翔
Zhang Min;Fang Jian;Wang Yong;Mo Wenxiong;Hao Fangzhou;Yang Fan;Lin Xiang(Guangdong Power Grid Co.,Ltd.,Guangzhou Power Supply Bureau,Guangzhou 510620,Guangdong,China;Key Laboratory of Medium-Voltage and Low-Voltage Electric Equipment Inspection and Testing of China Southern Power Grid,Guangzhou 510620,Guangdong,China)
出处
《激光与光电子学进展》
CSCD
北大核心
2022年第13期419-423,共5页
Laser & Optoelectronics Progress
基金
中国南方电网有限责任公司科技项目(GZHKJXM20180056)。
