Determination of particle size distribution based on dynamic light scattering measurements in the near field

Abstract

Particle size distribution (PSD) measurement is important for improving product quality, inhibiting environmental pollution, and safeguarding human health. The near-field scattering (NFS) technique offers many substantial advantages over conventional techniques. However, the reconstruction equations are ill-posed and it is difficult to get a reliable solution. In this paper, we propose a new method that can solve the reconstruction equations. This method combines the Backus-Gilbert eclectic theory with truncated singular value decomposition (TSVD) method to obtain a non-negative approximation solution as the initial value of Chahine algorithm for fine calculation. Our method exhibited good performance with several numerical cases of unimodal and bimodal PSDs. It was then used for PSD measurement of two standard particles (GBW(E) 120,028 and 120,047) using the NFS techniques. The relative errors of the length mean diameter, with respect to the peak size of these two standard particles, were 0.18% and 0.76%, respectively.