Simple Qualitative Modeling of Particle Size Analysis using Ray Tracing Method
Dellia Yulita(a), Muhammad Iqbal Rahmadhan Putra(a), Septian Ulan Dini(a), Erlina(a), Jessica (b, c), Arfat Pradana(c), Murni Handayani(d), Isa Anshori(b*, c), Sparisoma Viridi (a*,c).

a) Granular Physics and Fluids Laboratory, Nuclear Physics and Biophysics Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia
*dudung[at]fi.itb.ac.id

b) Lab-on-Chip Group, Biomedical Engineering Department, School of Electrical Engineering and Informatics, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia
* isaa[at]staff.stei.itb.ac.id

c) Research Center for Nanosciences and Nanotechnology (RCNN), Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia

d) Research Center for Metallurgy and Materials, Indonesian Institute of Sciences, Banten, 15314, Indonesia

Abstract

Understanding particle size analysis is essential for pharmaceutical, mining, environmental, coatings, and other industries. Although there are numerous technologies that can be utilized to take particle size measurements, the results of those measurements are presented automatically and are sometimes difficult to understand. In this study, using the ray-tracing method, simple qualitative modeling of particle size analyzers can be developed. The laser is positioned as the initial position of the light source in x and y directions. The cell is pictured by cuvettes with four surfaces clear, and the particle is modeled as a sphere. Reflection of a single ray of the laser beam on many spheres can be performed using single ray reflection on a single sphere consecutively until the beam leaving the observation region or arriving at a light sensor. Then with vector formulation of ray direction after reflection on many spheres system \(\hat{n}_r \) we can define \(\hat{n}_{r,n} = \hat{n}_{i,n-1} - 2(\hat{n}_{i,n-1}. \hat{n}_{p,n})\hat{n}_{p.n}\) with n = 1, 2, 3, ... where \(\hat{n}_{r,0} = \hat{n}_i\). As a test of the particle size analysis model, the results are compared with measurements of the monodisperse polystyrene latex. Interesting patterns in FFT and autocorrelation function results are found. Unfortunately, this finding is still considered inconclusive, due to the pattern obtained is not completely similar to the experimental results.

Keywords: Particle size analysis, ray tracing, qualitative model.

Topic: Modelling and Computational Physics