光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
Spectroscopy and Spectral Analysis
2015年
11期
2985-2989
,共5页
光谱技术%非相干宽带腔增强吸收光谱技术%HONO测量技术%NO2 测量技术
光譜技術%非相榦寬帶腔增彊吸收光譜技術%HONO測量技術%NO2 測量技術
광보기술%비상간관대강증강흡수광보기술%HONO측량기술%NO2 측량기술
Spectroscopy technique%Incoherent broadband cavity enhanced spectroscopy%HONO measurement technology%NO2 measurement technology
介绍了基于紫外LED光源的非相干宽带腔增强吸收光谱装置，并将其应用于实际大气中的HONO和NO2浓度的探测。中心波长为365 nm的UV‐LED出射光被耦合到～1.76 m长，由两片高反射率镜片组成的光学谐振腔内，透过腔的光由便携式CCD光谱仪接收。高反射率镜片的反射率由NO2和O2‐O2的吸收谱来校正，在353～376 nm的测量范围内，最高反射率为0.99917。在120 s的采集时间内，HONO和NO2的探测极限（1σ）分别为0.6和1.8 ppbv。将该装置测量的连续56 h大气中NO2浓度的变化与配备蓝光转换器的NOx 分析仪测量的结果进行比较，线性相关系数 R2＝0.89，斜率为1.09，截距为3.45。基于该装置探测了实验室大气中的 HONO和NO2昼夜浓度变化，24 h内的 HONO浓度在0～5.3 ppbv之间波动，平均浓度为1.8 ppbv ，NO2浓度变化范围为5～51 ppbv ，平均浓度为21.9 ppbv。
介紹瞭基于紫外LED光源的非相榦寬帶腔增彊吸收光譜裝置，併將其應用于實際大氣中的HONO和NO2濃度的探測。中心波長為365 nm的UV‐LED齣射光被耦閤到～1.76 m長，由兩片高反射率鏡片組成的光學諧振腔內，透過腔的光由便攜式CCD光譜儀接收。高反射率鏡片的反射率由NO2和O2‐O2的吸收譜來校正，在353～376 nm的測量範圍內，最高反射率為0.99917。在120 s的採集時間內，HONO和NO2的探測極限（1σ）分彆為0.6和1.8 ppbv。將該裝置測量的連續56 h大氣中NO2濃度的變化與配備藍光轉換器的NOx 分析儀測量的結果進行比較，線性相關繫數 R2＝0.89，斜率為1.09，截距為3.45。基于該裝置探測瞭實驗室大氣中的 HONO和NO2晝夜濃度變化，24 h內的 HONO濃度在0～5.3 ppbv之間波動，平均濃度為1.8 ppbv ，NO2濃度變化範圍為5～51 ppbv ，平均濃度為21.9 ppbv。
개소료기우자외LED광원적비상간관대강증강흡수광보장치，병장기응용우실제대기중적HONO화NO2농도적탐측。중심파장위365 nm적UV‐LED출사광피우합도～1.76 m장，유량편고반사솔경편조성적광학해진강내，투과강적광유편휴식CCD광보의접수。고반사솔경편적반사솔유NO2화O2‐O2적흡수보래교정，재353～376 nm적측량범위내，최고반사솔위0.99917。재120 s적채집시간내，HONO화NO2적탐측겁한（1σ）분별위0.6화1.8 ppbv。장해장치측량적련속56 h대기중NO2농도적변화여배비람광전환기적NOx 분석의측량적결과진행비교，선성상관계수 R2＝0.89，사솔위1.09，절거위3.45。기우해장치탐측료실험실대기중적 HONO화NO2주야농도변화，24 h내적 HONO농도재0～5.3 ppbv지간파동，평균농도위1.8 ppbv ，NO2농도변화범위위5～51 ppbv ，평균농도위21.9 ppbv。
We report on the development of an optical instrument based on LED‐IBBCEAS for simultaneous measurements of ni‐trous acid (HONO) and nitrogen dioxide (NO2 ) in ambient air .The light emitting from the LED centered at 365 nm was directly focused into the cavity formed with two high reflectivity mirrors ,separated by a distance of 1.76 m .The light output of the cavi‐ty was received with a portable spectrometer .The mirror reflectivity was calibrated by absorption spectra of NO2 and O2‐O2 .In the spectral range of 353~376 nm ,the maximum mirror reflectivity was found to be 0.999 17 .Detection limits (1σ) of 0.6 ppbv for HONO and 1.8 ppbv for NO2 were achieved with an acquisition time of 120 s .In order to test the accuracy of measured re‐sults by present setup ,concentrations of NO2 were recorded during continuous 56 hours and compared with data from a NOX an‐alyzer equipped with a blue light converter .The least‐square fit lines give gradients of 1.09 and respective intercepts of 3.45 , with a linear correction factor of 0.89 .The concentrations of HONO and NO2 in indoor air were monitored ,the concentrations of HONO varied from near 0 to 5.3 ppbv in 24 hours ,the averaged concentration was 1.8 ppbv ,and the concentrations of NO2 varied from 5 to 51 ppbv at the same time ,the averaged concentration was 21.9 ppbv .
