针对气体激光拉曼光谱分析受众多因素的影响导致定量测量的重复性不佳的难题,本文通过采集并分析大量光谱强度数据,提出一种精度更高,稳定性更好的计算光谱强度的算法,即"部分面积法"。同时比较不同面积计算光谱强度对测量重复性的影响。实验结果表明,在已设计的光路系统和采用的硬件设备的条件下,发现利用其中三点计算光谱强度,所得气体浓度的波动性最小、测量结果最稳定即测量重复性最佳。最后对10.0%C2H2气体浓度进行验证,连续测量的100组数据的标准差达到8.526 2×10^-4,并给出了相应的初步理论分析。
In view of the gas Raman spectrum analysis affected by many factors that lead to poor repeatability of measurement. A method which we called "partial area method" with higher accuracy and well stability is proposed to calculate the intensity of the Raman spectra by collecting and analyzing a large amount of spectral intensity data. What's more, the influence of different area to calculate spectral intensity on measurement repeatability is compared. Experimental results show that using three-point area to calculate the intensity of the Raman spectra has smallest gas concentration fluctuation and most stable measurement result which is called best measurement repeatability under the design of optical systems and hardware conditions. Finally, the concentration of 10.0% C2H2 gas had been verified by the standard deviation of 100 sets of data which can reach 8.526 2×10^-4. And the corresponding preliminary theoretical analysis is presented.