内调制激光差分NO_2检测  

Detection of nitrogen dioxide based on laser internal modulation and differential detection

作　　者：李金艳[1] 高致慧[1] 林伟豪[1] 杨勇[1] 贺威[1] 李辉[1] 

机构地区：[1]深圳大学电子科学与技术学院,广东深圳518060

出　　处：《激光与红外》2015年第8期948-951,共4页Laser & Infrared

基　　金：深圳市知识创新计划项目(No.JCYJ20130329142116637)资助

摘　　要：为了实时检测空气中NO2的浓度,采用差分检测与内调制技术相结合的方法设计了一套激光NO2检测系统。该系统采用波长为450 nm的蓝光激光器作为光源,这是根据NO2吸收峰特点选取的。采用光源内调制技术,通过TTL调制驱动电流实现对输出光强及其频率的调制。在常温常压下,对NO2浓度进行了测量,并用最小二乘法对实验数据进行了处理。结果表明,实验系统的最低浓度检测极限是6 ppm,拟合系数R2为0.9996。A nitrogen dioxide （NO2 ）detecting system based on laser internal modulation and differential detection was designed in order to real-time monitor NO2 concentration in the air.According to the characteristics of NO2 ab-sorption peak,the blue laser operating at 450nm was selected as the light source.The internal modulation technology was used,and the output light intensity and frequency were controlled through modulating the drive current by TTL （Transistor-Transistor Logic）.The NO2 concentration was measured at room temperature and atmospheric pressure, and experimental data were processed with the least square method.The results show that the detection limit of the system is 6ppm and a fitting coefficient is 0.9996.

关 键 词：吸收光谱法 差分检测技术 内调制 NO2 最小二乘法 

分 类 号：O433.4[机械工程—光学工程]