微粒粒度分布FD测量法的改进

Improvement of FD method to measure the distribution of particles' sizes

基于Fraunhofer Diffraction原理测量粒度分布的方法应用已久 ,然而 ,在实际应用中由于SSPD等光电器件性能的限制和反演中数学近似的误差影响了测量效果。对此 ,充分讨论了衍射中心的正确测定对测量效果的影响以及PSD的定位特性和 3D CCD的响应特性 ,并由此提出了PSD光强重心定位法和CCD的RGB均衡法 ,有效地解决了衍射中心确定、峰值饱和、散射连续响应、散射角θ的分辨率等问题 ,同时结合Shifrin积分变换对测量进行了改进 ,较好地获得了微粒的连续粒度分布谱图n(D)。

The method to measure the distribution of particles' size based on FD principle has been applied for a long time.However its results are affected by the limitation of SSPD and the error of inversion method itself.In the paper,the effect of diffration image central framing,the characters of PSD and CCD response property are studied.Then two methods,i.e. the central framing by PSD and RGB equilibrium by CCD for the diffraction image receiving are put forward,which settle the problem of precision of central framing and determination of r and θ and meanwhile escape the problem of peak value saturation by a CCD. Finally, a continual distribution I(θ) is obtained and the distribution of particles' size n(D) is inverted accurately upon the Shifrin inversion in the measurement.