采用同轴数字全息技术测量研究粒子场,其高分辨力的再现像和粒径高精度测量受到诸多因素的影响。本文简要介绍了同轴数字全息的基本概念、原理、方法及其在粒子直径测量中的应用,主要通过计算机仿真研究了记录距离和粒子浓度这两个因素对粒径测量精度的影响,给出了记录距离的范围,同时提出了基于灰度梯度提取粒子边缘进行粒径测量的方法,并通过实验进行了验证。

The basic concept and procedure of digital in-line holography are shown mainly for particle diameter measurement. The result of the reconstructed image and the particle diameter measurement are affected by some recording parameters, i.e. recording distance, particle density, the size of CCD chip and the pixel size, etc. These recording parameters may even determine the success or failure of the measurement. Two parameters, recording distance and particle density, are mainly discussed for particle diameter measurement through computer simulation. The range of recording distance is given by formula. Simultaneously, a kind of method for particle diameter measurement based on gray gradient by extracting particle edge is put forward and verified by experiment.