CAJ | 학술논문

介绍了一种以1665 nm分布反馈(DFB)激光器为光源,使用双光路差分吸收光谱技术(DAS)测量甲烷浓度的检测系统.双光路差分吸收光谱技术能有效抑制由于光源光强变化、探测器零点漂移等因素所引起的测量的不准确.文中对这种检测方法进行了理论和实验分析,系统的最小探测浓度为100×10~(-6),响应时间约为14 s.
개소료일충이1665 nm분포반궤(DFB)격광기위광원,사용쌍광로차분흡수광보기술(DAS)측량갑완농도적검측계통.쌍광로차분흡수광보기술능유효억제유우광원광강변화、탐측기영점표이등인소소인기적측량적불준학.문중대저충검측방법진행료이론화실험분석,계통적최소탐측농도위100×10~(-6),향응시간약위14 s.
There has been considerable interest in methane sensors based on infrared absorption spectroscopy recently for industrial detection and environment monitoring.A DFB LD in the 1665nm region has been utilized as a light source for differential absorption measurement in the sensing of methane.The light output from the DFB LD is split into two beams by a half mirror.One of the beams is used for sensing methane (sensing light beam) while the other is used for wavelength calibration (reference beam).The sensing light beam has been adjusted to coincide with one of the methane 2v_3 absorption lines,and it has been monitored by PbSe PD1 (photo diode) after being passed through the testing cell.The reference beam which is free from absorption has been monitored by PD2.Dividing the sensing signal by the reference is also investigated to increase the sensitivity.The system can detect methane down to 100×10~(-6),and the response time is about 14 s.