基于二阶导数谱与特征吸收窗的红外光谱定量检测方法

发布时间：2018-02-05 19:09

本文关键词： 红外定量检测二阶导数谱 Savitzky-Golay滤波器特征吸收窗　出处：《光谱学与光谱分析》2017年06期 　论文类型：期刊论文

【摘要】：红外光谱分析技术已被液体、固体和气体混合物各组分的定量检测广泛应用。针对红外光谱定量检测过程中存在的计算过程复杂、受背景及噪声干扰、多组分谱线混叠的问题,一方面,通过获取谱线二阶导数去除背景及噪声干扰,并一定程度上区分混叠谱峰。在获取二阶导数谱线过程中运用Savitzky-Golay滤波器进行平滑滤波处理,并根据谱线频率特征选取Savitzky-Golay滤波器最佳滤波参数,解决了滤波参数缺乏标准化选取方法的问题。另一方面,根据被测组分的吸收分布情况生成特征吸收窗分别对待测原始吸收谱线以及二阶导数谱线加以处理,提取出在浓度计算过程中占据重要性更大的特征吸收的区域,从而排除非吸收区域中背景、噪声及其他组分对计算结果的干扰。以一组丙烷、丙烯和甲苯混合气体为例,运用二阶导数方法以及特征吸收窗方法进行定量检测,并与直接利用原始谱线的检测结果进行比较分析。实验结果表明采用二阶导数谱与特征吸收窗的定量检测方法精度更高,相对误差基本在5%以内。
[Abstract]:Infrared spectrum analysis technology has been widely used in quantitative detection of components of liquid, solid and gas mixtures. In view of the complex calculation process in the process of infrared spectrum quantitative detection, it is interfered by background and noise. On the one hand, the second derivative of spectral lines is obtained to remove background and noise interference. To some extent, the aliasing spectrum peak is distinguished. In the process of obtaining the second derivative spectral line, Savitzky-Golay filter is used to smooth filter. The optimal filter parameters of Savitzky-Golay filter are selected according to the spectral line frequency characteristics, which solves the problem of the lack of standardized selection method of filter parameters. On the other hand. According to the absorption distribution of the tested components, the characteristic absorption window is generated to treat the original absorption line and the second derivative spectrum line respectively. In order to eliminate the interference of background, noise and other components in the non-absorption region, a group of propane was extracted to occupy the more important characteristic absorption region in the calculation of concentration. The second derivative method and the characteristic absorption window method were used for quantitative detection of propylene and toluene mixtures. The experimental results show that the quantitative detection method based on the second derivative spectrum and the characteristic absorption window is more accurate and the relative error is less than 5%.
【作者单位】：河北工业大学机械工程学院;天津大学精密测试技术及仪器国家重点实验室;天津工业大学天津市电工电能新技术重点实验室;
【基金】：河北省自然科学基金项目(F2014202065) 国家重大科学仪器设备开发专项(2012YQ06016501) 国家自然科学基金项目(61505142)资助
【分类号】：O657.33

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