Educ. Reso. for Part. Techn. 032Q-Wedd
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Copyright © 2003 Maurice W. Wedd, Licensed to ERPT

Detemination of Particle Size Distribution
Using Laser Diffraction

by Maurice W. Wedd

Malvern Instrument Co. www.malvern.co.uk
Email: maurice.wedd@malvern.co.uk
Received: 2002 Nov 25; Accepted: 2003 Mar 20

Note: The tutorial sections are posted as PDF files.

Outline

Part 1
      Introduction
      Dependence of light scattering
            on particle size and refractive index
            on the number of particles in the beam
            on the angle of observation
Part 2
      Lower limit for analysis using light scattering
      Large particles and the Fraunhofer approximation
      Using light polarization in size analysis
Part 3
      Examples of getting it wrong
      How can appropriate refractive index values be determined?
      How can we finally confirm our choice of refractive index?
      References

Maurice W. Wedd, a Chartered Engineer in the IEEE, was trained as an electronics engineer through part-time study at Technical College and company training within E.K Cole, Ltd., who produced Radar and Nucleonics equipment. His early work included hand-calculating the backscatter expected from a 3 mm raindrop illuminated with a 3 cm wavelength radar. He joined Malvern Instruments Ltd in May 1970 and shifted wavelengths to 0.633 nm, helping develop photon correlation spectroscopy, laser diffraction and zeta potential equipment. He is chairman of the British Standards Institute technical committee -- overseeing and participating in the work of ISO TC24/SC4 (Particle Sizing other than Sieving). He is also treasurer of the Particle Characterisation Interest Group of the Royal Society of Chemistry, which arranges technical seminars and training days.
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