基于TDLAS的气相过氧化氢浓度测量技术的研究

发布时间：2018-03-29 20:01

本文选题：气相过氧化氢　切入点：可调谐半导体激光吸收光谱　出处：《浙江大学》2015年硕士论文

【摘要】：近年来,气相过氧化氢应用于杀菌消毒的场景越来越广泛,但是目前缺乏对气相过氧化氢有效的在线检测手段。本文基于可调谐半导体激光吸收光谱(TDLAS)原理进行了气相过氧化氢传感系统的研究。TDLAS测量原理的理论基础是Beer-Lambert定律,本文第二章重点介绍了该定律的物理意义,对波长调制技术进行了理论阐述,了解了利用二次谐波信号反演出气体浓度值。介绍了利用HITRAN数据库查询气体吸收峰的方法。利用TDLAS原理进行气体浓度检测的一个重点问题是确定目标气体的吸收谱线。由于高精度分子跃迁吸收数据库中尚未更新气相过氧化氢在近红外波段的’吸收谱线数据,本实验的难点之一便是寻找气体在近红外波段的吸收峰。结合文献调研和电流、温度调节的办法,本文实验成功找到了目标气体的一个较强吸收吸收峰。在找到气相过氧化氢的吸收峰之后,实验的另一个重点内容便是编程处理得到的实验数据。本文实验基于Lab VIEW给出了具体的处理程序,通过GPIB控制锁相放大器时序采集二次谐波信号和一次谐波信号,将实时采集到的二次谐波与一次谐波信号相除并扣除背景噪声,所得信号的吸收峰的值即为实验得到的相对浓度值。实验还研究了初始时刻信号的稳定性、以及湿度对实验测量的影响,验证了TDLAS系统的稳定性,并且给出了湿度影响的解决办法。最后通过多台电化学传感器同时测量的方法标定TDLAS相对浓度值,给出了实验系统的拟合多项式,得到系统精度为25ppm,探测范围为100-1500ppm,灵敏度为1543ppm/V,从而实验验证了TDLAS系统的可行性。
[Abstract]:In recent years, gaseous hydrogen peroxide has been widely used in sterilization and disinfection. However, there is no effective on-line detection method for gas phase hydrogen peroxide. In this paper, the gas phase hydrogen peroxide sensing system based on tunable semiconductor laser absorption spectroscopy (TDLAS) is studied. The theoretical basis of the measurement principle of TDLAS is Beer-Lambert 's law. In the second chapter, the physical meaning of the law is introduced, and the wavelength modulation technology is described theoretically. The method of querying gas absorption peak by using HITRAN database is introduced. A key problem of gas concentration detection using TDLAS principle is to determine the absorption of target gas. Spectral lines. As the 'absorption line data of gaseous hydrogen peroxide in the near infrared band have not been updated in the high-precision molecular transition absorption database, One of the difficulties of this experiment is to find the absorption peak of gas in near infrared band. In this paper, we have successfully found a strong absorption peak of the target gas, after finding the absorption peak of hydrogen peroxide in the gas phase, Another important content of the experiment is the experimental data which is processed by programming. Based on Lab VIEW, a specific program is given in this paper. The second harmonic signal and the first harmonic signal are collected by the GPIB control phase locked amplifier, and the second harmonic signal and the first harmonic signal are collected by the GPIB control amplifier. The second harmonic signal and the first harmonic signal collected in real time are divided and the background noise is deducted. The value of the absorption peak of the obtained signal is the relative concentration obtained from the experiment. The stability of the signal at the initial time is also studied in the experiment. The stability of TDLAS system is verified and the solution of humidity effect is given. Finally, the relative concentration of TDLAS is calibrated by multiple electrochemical sensors simultaneously. The fitting polynomial of the experimental system is given. The precision of the system is 25ppm, the detection range is 100-1500ppm, and the sensitivity is 1543ppm / V, thus the feasibility of the TDLAS system is verified experimentally.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ123.6;TN249

【参考文献】