摘要
研究了中心波长分别为370nm(近紫外)、452nm(蓝光)和660nm(红光)三种无标准具结构的发光二极管(LED)光源温度波动对差分吸收光谱技术(DOAS)测量NO2的影响。利用温度10℃时的LED灯谱构造NO2吸收谱,将其他温度下测得的LED谱作为灯谱,以此得到不同温度波动下的NO2差分光学密度,再拟合NO2差分吸收截面到差分光学密度,结果发现拟合残差的峰-峰值与LED温度波动幅度均近似成线性关系,相关性分别为0.995,0.945和0.989;斜率分别为1.12×10-3,5.25×10-5和7.45×10-4℃-1。拟合结果表明,蓝光LED温度波动对DOAS反演影响最小,基本上不影响探测灵敏度,而近紫外和红光LED温度波动对DOAS测量较为敏感,温度波动会导致探测灵敏度的下降。将温度特性相似的有、无标准具结构的两种蓝光LED的反演结果进行了比较,结果显示标准具结构会大幅度增加温度波动对DOAS反演的影响。
Influences of LEDs（without etalon structure and center wavelengths are respectively 370 nm（near-UV）,452 nm（blue） and 660 nm（red）） temperature shifts on differential optical absorption spectroscopy（DOAS） for measuring NO2 were studied.NO2 absorption spectra were formed using LED emitting spectra at 10 ℃.The measured LED spectra at other temperatures were used as reference spectra of DOAS.Thus,NO2 differential optical densities under different LED temperature shifts were acquired and then NO2 differential cross-sections were fitted to the acquired differential optical densities.From fitting results,the linear relations of 0.995,0.945 and 0.989 correlation between delta of fitting residual and near-UV,blue and red LEDs temperature shifts were found and their slopes are respectively 1.12×10-3,5.25×10-5 and 7.45×10^-4 ℃^-1.The fitting results show that the influence of temperature shifts of blue LED on DOAS retrieval is negligible and the temperature shifts of near-UV and red LED are impressible to DOAS measurement resulting in degradation of detection sensitivity.The retrieval results of blue LED with and without etalon with similar temperature properties were compared and showed that etalon of LED will greatly increase the influence of temperature shifts of LED on DOAS retrieval.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2012年第11期2886-2890,共5页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金青年科学基金项目(60808034
40905010)
国家(863计划)项目(2009AA063006)资助
关键词
差分吸收光谱技术
发光二极管
温度波动
NO2测量
Atmospheric optics
Differential optical absorption spectroscopy
Light emitting diode
Temperature shift
NO2 measurement
