基于波长调制光谱技术的免标定单线测量法

发布时间：2018-05-17 04:08

本文选题：光谱学 + 单线法　；参考：《光学学报》2017年09期

【摘要】：可调谐二极管激光吸收光谱技术一般采用双线法同时测量气体的温度和物质的量分数。然而在频分和时分复用这两种方式下,双线法易存在频率串扰和降低时间分辨率等问题,在实际应用中有一定的局限性。针对此问题,提出了基于波长调制光谱技术的免标定单线测量法,只用一条吸收谱线即可实现对气体温度和物质的量分数的同时测量。以燃烧过程中的主要产物CO_2为目标气体,选择中心频率为5007.787cm-1的吸收谱线R(50)进行实验验证。从扣除背景的峰值归一化二次谐波信号的线型中提取温度信息,再利用扣除背景的一次谐波归一化二次谐波信号提取CO_2的物质的量分数。实验结果表明,免标定单线法与热电偶测量的温度最大相对偏差小于2.5%,物质的量分数的最大相对偏差小于2.8%。验证了用免标定单线测量法同时测量CO_2的温度和物质的量分数是可行的。
[Abstract]:Tunable diode laser absorption spectroscopy is usually used to measure the temperature and mass fraction of gas simultaneously. However, in the two ways of frequency division and time division multiplexing, the problems of frequency crosstalk and time resolution reduction are easy to exist in the two-wire method, which has some limitations in practical application. In order to solve this problem, a single line measurement method based on wavelength modulation spectroscopy is proposed, in which the temperature and mass fraction of gas can be measured simultaneously with only one absorption line. CO_2, the main product of the combustion process, was chosen as the target gas, and the absorption line R _ (50) with the center frequency of 5007.787cm-1 was selected for experimental verification. The temperature information is extracted from the linear form of the normalized second harmonic signal with the peak value of the subtraction background, and the quantity fraction of the substance of CO_2 is extracted by using the normalized second harmonic signal of the subtraction background. The experimental results show that the maximum relative deviation of temperature is less than 2.5 and the maximum relative deviation of mass fraction is less than 2.8. It is proved that it is feasible to measure the temperature and mass fraction of CO_2 simultaneously by using the method of free calibration single line measurement.
【作者单位】：东南大学能源与环境学院;
【基金】：国家重大科学仪器设备开发专项(2014YQ06053701) 国家自然科学基金(50976024);国家自然科学基金青年科学基金(50906013)
【分类号】：O433

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