Today one of the most common applications of Mie theory is in providing a rigorous solution for calculating particle size distributions from laser diffraction light scattering data
Alan Rawle, divisional applications manager for Malvern Instruments and widely known as an expert in particle characterisation techniques, will present a paper celebrating 100 years of Mie theory at the 11th Electromagnetic and Light Scattering Conference to be held from 7-12 September 2008 at the University of Hertfordshire, UK.
While early laser diffraction systems used an alternative mathematical approximation, it is the application of Mie theory, together with advances in optical design, which have enabled the measurement of particles over a very wide dynamic range.
According to Rawle: "The implementation of Mie theory in the Malvern Mastersizer 2000, for example, allows the measurement of particles from 0.02 to 2000 microns in size.
"Being able to characterise particles over such a broad range, using a single optical setup, delivers many benefits to users in terms of product understanding and quality control".
Since the use of Mie theory requires a knowledge of the refractive index and absorption of the materials being measured, the Mastersizer 2000 has a built in database of optical properties.
In his presentation Rawle will explore the impact of using Mie theory correctly and will provide some practical rules for selecting the appropriate optical property values for materials as diverse as ceramics and food emulsions.
