在光全散射法颗粒粒径测量中,采用独立模式算法在可见-红外波段对粒径测量范围进行了深入的研究。通过对多种R-R分布函数反演结果进行分析,比较,以确定光全散射法颗粒粒径测量范围。同时在消光系数计算中,采用修正的消光系数代替原始的消光系数,以便得到更准确的粒径测量范围。仿真计算结果表明,在可见-红外光谱区,相对折射率m=1.235时的粒径测量范围为0.05-18μm。在此区域内测量粒径分布,反演结果与真值基本吻合。随着颗粒相对折射率、波长范围的变化,粒径测量范围也随之发生改变。采用限制最小二乘算法能够最大限度地克服随机噪声对测量结果的影响,使测量的精度和可靠性明显提高。对测量的消光值加入±1%随机噪声时,颗粒粒径分布的反演均能得到满意的结果。
The problem of determining the particle size range in the visible-infrared region was studied using the independent model algorithm in the total scattering technique.By the analysis and comparison of the accuracy of the inversion results for different R-R distributions,the measurement range of particle size was determined.Meanwhile,the corrected extinction coefficient was used instead of the original extinction coefficient,which could determine the measurement range of particle size with higher accuracy.Simulation experiments illustrate that the particle size distribution can be retrieved very well in the range from 0.05 to 18 μm at relative refractive index m= 1.235 in the visible-infrared spectral region,and the measurement range of particle size will vary with the varied wavelength range and relative refractive index.It is feasible to use the constrained least squares inversion method in the independent model to overcome the influence of the measurement error,and the inverse results are all still satisfactory when 1% stochastic noise is added to the value of the light extinction.