颗粒系的可见消光光谱分析及最佳波长的选择  

Analysis of Visible Extinction Spectrum of Particle System and Selection of Optimal Wavelength

作　　者：孙晓刚[1] 唐红[1] 原桂彬[1] 

机构地区：[1]哈尔滨工业大学自动检测与过程控制系统研究所,黑龙江哈尔滨150001

出　　处：《光谱学与光谱分析》2008年第9期1968-1973,共6页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(50336010)资助

摘　　要：在光全散射法颗粒粒径测量中,被测颗粒系的消光光谱包含有颗粒粒径、折射率等信息。对常用的单峰及双峰R-R分布的可见消光光谱进行模拟,分析了可见消光光谱随粒径和相对折射率变化的规律。选取二阶微分可见消光光谱不连续点对应的波长作为测量波长,并将可见光边界波长同时作为测量波长,在非独立模式下,采用遗传优化算法反演粒径分布。仿真计算与实验验证结果表明,通过消光光谱分析,可以预先确定被测颗粒系的分布状况,缩小优化算法中反演参数的搜索范围。结合最佳波长选择方法,使测量的精度和可靠性明显提高。对测量光谱加入1%随机噪声时,单峰及多峰分布粒径反演均能得到满意的结果。In the total light scattering particle sizing technique, the extinction spectrum of particle system contains some information about the particle size and refractive index. The visible extinction spectra of the common monomodal and biomodal R-R particle size distribution were computed, and the variation in the visible extinction spectrum with the particle size and refractive index was analyzed. The corresponding wavelengths were selected as the measurement wavelengths at which the second order differential extinction spectrum was discontinuous. Furthermore, the minimum and the maximum wavelengths in the visible region were also selected as the measurement wavelengths. The genetic algorithm was used as the inversion method under the dependent model. The computer simulation and experiments illustrate that it is feasible to make an analysis of the extinction spectrum and use this selection method of the optimal wavelength in the total light scattering particle sizing. The rough contour of the particle size distribution can be determined after the analysis of visible extinction spectrum, so the search range of the particle size parameter is reduced in the optimal algorithm, and then a more accurate inversion result can be obtained using the selection method. The inversion results of monomodal and biomodal distribution are all still satisfactory when 1% stochastic noise is put in the transmission extinction measurement values.

关 键 词：粒径测量 光全散射法 可见消光光谱 最佳波长 

分 类 号：TH744[机械工程—光学工程] O436[机械工程—仪器科学与技术]