夫琅和费衍射颗粒粒度测量中的改进Chin-Shifrin反演算法

在基于线阵CCD的夫琅和费衍射颗粒粒度测量中,采用Chin-Shifrin积分变换反演算法使得反演的粒度分布出现假峰现象.为解决此问题,提出在该Chin-Shifrin积分变换反演算法中引入矩形窗函数,并在分析颗粒粒径与衍射光强导数最小值之间关系的基础上,确定矩形窗函数中心点位置及左右边界,利用该矩形窗函数对粒度分布进行截断处理,消除虚假峰,提高反演颗粒粒度分布的准确性.分别对两种标准颗粒进行了测量,并对不同算法的反演结果进行了对比.实验结果表明:引入矩形窗函数的改进Chin-Shifrin算法,能够有效排除粒度分布中的多假峰;粒度分布测量相对误差小于3%,重复性小于4%.

Improved Chin-Shifrin Algorithm in the Measurement of Particle Sizing Used by Fraunhofer Diffraction Method

In the measurement of particle size by Fraunhofer diffraction method based on a linear CCD,the Chin-Shifrin inversion algorithm can lead to false peaks in the inversion of Particle Size Distribution (PSD).To overcome this phenomenon of the algorithm,a rectangular window function was proposed and introduced in this algorithm.The midpoint and boundary of the window function were determined by analyzing the relationship between particle size and its minimum value of derivative of the diffraction light intensity.The inverted PSD was truncated by superposing the window function to remove the false peaks and enhance the accuracy of the inverted PSD.The results of the inverted PSDs obtained by using different algorithms were compared by measuring two types of standard materials respectively.Experimental results show that,the improved Chin-Shifrin algorithm can effectively eliminate the false peak distributions in the inverted PSD.The relative error of the measuring results is less than 3 ％,and the repeatability is no more than 4 ％.