光阻法颗粒粒径测量验证实验

Experiment on particle size measurement and verification using light-blockage method

针对低浓度液体介质中颗粒物的数目和粒径检测问题,基于几何光学原理和Mie光散射理论分析,研究光阻法对球形颗粒的检测,采用角散射并结合图像法验证信号测量的一致性。搭建了一套能采用3种方法同步测试的实验系统,通过对实验测得的6种标准颗粒的光阻信号进行标定,对不同标准颗粒脉冲幅值进行统计平均后拟合和优化,通过拟合公式进一步测定了其他颗粒的粒径。结果表明,对于标称为15.0μm和63.6μm标准颗粒的数目中位径与标称值偏差均小于2%,同时对于混合颗粒也具有较好的区分能力。

In order to detect and analyze the number and size of particulate matter in liquid media,the characterization of standard spherical particles were investigated by the method of lightblockage related to geometric optics and Mie scattering theory,while the method of angle scattering and the image method were used to verify the consistency of the measurement.A system was established that could be available simultaneously for the three methods.To perform a calibration,the amplitudes of obtained light-blockage signal for standard particles with six different sizes were statistically averaged and fitted,which consequently provided a fitting formula to determine the measurement results of other particles.The results for two standard particles and a mixed particle system showed that the median diameters for particles with nominal value of both 15.0μm and 63.6μm yielded a deviation less than 2%,and the mixed particles were also well identified in size.