基于TDLAS技术的气体分析仪在线纠偏方法研究  

Research on Online Corrective Method of Gas Analyzer Based on TDLAS Technology

作　　者：刘立富 吴强 冯雨轩 苏光旭 陈建龙 陈东 刘凡新 LIU Lifu;WU Qiang;FENG Yuxuan;SU Guangxu;CHEN Jianlong;CHEN Dong;LIU Fanxin(College of Science,Zhejiang University of Technology,Hangzhou 310023,China;Hangzhou Zetian Chunlai Technology Co.,Ltd.,Hangzhou 310052,China)

机构地区：[1]浙江工业大学理学院,浙江杭州310023 [2]杭州泽天春来科技股份有限公司,浙江杭州310052

出　　处：《自动化仪表》2024年第11期13-18,29,共7页Process Automation Instrumentation

基　　金：国家自然科学基金资助项目(11974015);浙江省自然科学重点基金资助项目(LZ22A040008)。

摘　　要：基于可调谐半导体激光吸收光谱(TDLAS)技术的气体分析仪由于环境温度变化或电子器件长期老化等会引起激光器温控漂移,从而导致被测气体谐波信号偏移。通过设计分光参比光路、参比接收电路和软件纠偏流程,利用参比谐波信号作为纠偏判断的参考信号,实现了气体在线监测和实时在线纠偏。试验采用信号处理单元对比参比谐波信号中心点与预设中心点,根据纠偏阈值、纠偏范围等纠偏参数判断是否执行纠偏动作。试验结果表明,采用参比信号比测量信号判定纠偏更加适合低浓度气体检测的应用,可有效避免未纠偏和误纠偏。该方法可解决复杂环境因素变化导致谐波信号偏移的问题,提高基于TDLAS技术的气体分析仪应用的可靠性和稳定性。The gas analyzer based on tunable diode laser absorption spectroscopy(TDLAS)technology can cause drift of the temperature control of the laser caused by changes in the ambient temperature or long-term aging of the electronic devices,which can lead to the harmonic signal of the measured gas to be offset.By designing the spectroscopic reference optical circuit,reference receiving circuit and software correction process,the gas online monitoring and real-time online correction are realized by using the reference harmonic signal as the reference signal for correction judgment.The test adopts a signal processing unit to compare the center point of the reference harmonic signal with the preset center point,and judges whether to carry out the corrective action according to the corrective parameters such as the corrective threshold value and corrective range,etc.The test results show that the use of the reference signal to judge correction is more suitable for the application of low concentration gas detection than the measurement signal,and can effectively avoid the non-correction and mis-correction.This method can solve the problem of harmonic signal offset caused by the change of complex environmental factors,and improve the reliability and stability of the application of the gas analyzer based on TDLAS technology.

关 键 词：光谱分析 可调谐半导体激光吸收光谱 谐波信号 在线纠偏 气体监测 分光参比 

分 类 号：TH744[机械工程—光学工程]