for Physical Chemists by Physical Chemists


Combined technologies for particles size, shape and concentration measurement

F. Devreese, Ankersmid, Wilrijk, Belgium

The EYETECH particle size, shape and concentration analyzer has been developed for research as well has quality control purposes and combines two methods of analysis.

The analyzer has two optical channels:

  • a laser channel that uses the laser obscuration time method . the laser obscuration time method is based on the interaction of a rotating laser with a particle which creates an “obscuration time” pulse. Analysis of the pulse width yields the size of the particle. The rotating laser beam describes an optical volume and by counting the particles going through this optical volume, concentrations can me measured
  • Dynamic Image analysis channel :dynamic visualization shows the particles in the measuring zone of the monitor. Two dimensional analysis of video images enables the determination of different shape and size parameters such as Ferret diameters, Shape factor, Aspect ratio calculation, etc. In addition discriminations of particles by using strategic shape filters is available.

The combination of measuring concentration, shape and size parameters at the same time on the same sample allows the user to use the analyzer in a very broad spectra of applications like dissolution kinetics or in modeling applications and is a powerful tool in the hands of Quality control engineers giving them more then 40 particle size and/or shape parameters to consider.

Contact person: Devreese F
Neerlandweg 22A
B-2610 Wilrijk
Tel: +32 498 88 03 51
Fax: +32 230 98 58, e-mail (

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Last modified: 28 April 2008