摘要
为了克服传统方法检测氧气浓度的一些弊端,提出了一种采用可调谐激光二极管吸收光谱法结合锁相放大的检测技术。通过改变激光二极管的驱动电流使输出波长变化扫描通过氧气的吸收峰,然后利用锁相放大技术对吸收光谱的谐波进行检测分析。利用半导体激光能量高、单色性好、输出波长可随电流调制的特点和锁相放大检测微弱信号的优势来提高信噪比与检测精度。对不同浓度的氧气进行了实际检测,可得检测线性相关系数为0.99.检测极限质量浓度为1142.86 mg/m^3,且该方法具有较好的稳定性及抗干扰性。
To overcome some disadvantages of traditional methods to measure the oxygen concentration, the tunable diode laser absorption spectroscopy combined with the phase-lock amplifier is studied. By tuning the drive current of the laser diode （LD） to change the output wavelength, one or more absorption peaks of the oxygen will be scanned. And then the phase lock technique will be used to analyze the harmonic signal of the absorption spectroscopy. This method combines the high power, good monochrome, wavel.ength easily tuned with the drive current and the advantage of phase-lock amplifier to improve the signal and noise ratio and the measure precision. Through the measurements of some different concentration oxygens, the correlation coefficient of the result is 0.99 and the detection limit is 1142.86 mg/ma, moreover the method has the good stability and anti-interference feature.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2008年第10期1558-1562,共5页
Chinese Journal of Lasers
基金
国家863计划(2006AA06Z410)
天津市自然科学基金(06YFJMJC06700)资助项目
关键词
光学柃测
可调谐激光
锁相
氧气
波长调制
optical test
tunable diode laser
phase lock
oxygen
wavelength modulation
