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Brochure and specifications

Publications

Traditional Mass Measurement of Ultrafines

Historically the Differential Mobility Analyzer (DMA) has been used to classify nanoparticles by electrical mobility. This technique has become an internationally accepted standard for ultrafine particle size measurement.

The classification in a DMA depends on the ratio between electrical charge and aerodynamic drag on each particle. Since both of these parameters depend on particle morphology, techniques to calculate ultrafine particle mass using DMA measurements have required empirical factors to account for varying particle morphology.

Direct Nanoparticle Mass Measurement

The difficulties associated with morphology and electrical mobility measurement are overcome by techniques which measure the mass directly. A technique which does this by balancing the electrostatic and centrifugal forces on a particle was first described by Ehara et al. in 1996.

The Centrifugal Particle Mass Analyzer

The Centrifugal Particle Mass Analyzer (CPMA) instrument is the embodiment of a further refinement for classifying ultrafine particles directly by mass. Originally conceived by Cambustion in 2004, launch of the production CPMA was announced at the AAAR annual conference 2010.

The CPMA uses opposing electrical and centrifugal fields to classify particles, with the ability to vary the electrical field and rotation speed to select different particle masses.

Unique features of the CPMA (see the animation for details) allow a very high transmission efficiency of particles with the selected mass, making the CPMA attractive for a range of applications.