基于可调谐半导体激光吸收光谱技术的甲烷气体监测研究

Study on Methane Gas Monitoring Based on Tunable Semiconductor Laser Absorption Spectrum Technology

设计了一种基于可调谐半导体激光吸收光谱技术的甲烷(CH4)气体监测装置,该装置具有温度监测范围大、监测精度高和实时监测的优点。监测装置的激光光源为波长1650 nm的反馈式激光器,应用波长调谐与锁相放大器技术,对周围环境进行温度补偿与背景扣除,可以较准确地测量周围环境中CH4的体积分数。实验表明,当CH4体积分数小于1%时,该装置的监测精度为±0.02%;当CH4体积分数大于1%时,装置监测误差小于±0.8%,实时监测的最长响应时间为10 s。装置的温度范围为0~40℃,可满足大多数工业生产中对CH4等气体体积分数的监测需求。

This paper designed a methane(CH4)gas monitoring device based on tunable semiconductor laser absorption spectrum technology,which has the advantages of wide temperature monitoring range,high monitoring accuracy and real-time monitoring.The laser source of the monitoring device is a feedback laser with a wavelength of 1650 nm.By using the technology of wave-length tuning and lock-in amplifier,the temperature compensation and background subtraction are carried out in the surrounding environment,and the volume fraction of CH4 in the surrounding environment can be measured more accurately.The experimental results show that when the CH4 volume fraction is less than 1%,the monitoring accuracy of the device is±0.02%;when the CH4 volume fraction is greater than 1%,the monitoring error of the device is less than±0.8%,and the longest response time of real-time monitoring is 10 s.The temperature range of the device is 0-40℃,which can meet the monitoring requirements of CH4 and other gas volume fractions in most industrial production.