Particle mass analyser is a measurement technique for classifying

aerosol An aerosol is a suspension (chemistry), suspension of fine solid particles or liquid Drop (liquid), droplets in air or another gas. Aerosols can be natural or Human impact on the environment, anthropogenic. Examples of natural aerosols are fog o ...

particles according to their mass-to-charge ratio. Techniques exist for classifying (selecting) aerosol particles in the sub 1,000 nm range according to

electrical mobility Electrical mobility is the ability of charged particles (such as electrons or protons) to move through a medium in response to an electric field that is pulling them. The separation of ions according to their mobility in gas phase is called ion ...

using devices such as differential mobility analysers.

Electrical mobility

In electrical mobility measurement, aerosol particles are classified according to their aerodynamic drag-charge ratio. If the particle is non-spherical, the electrical-mobility diameter will not correspond to any measurable physical dimensions of the particle. (For a spherical particle, the electrical-mobility diameter will correspond to physically measurable diameter.)

Centrifugal particle mass analyzer

An alternative technique classifies particles according to their

mass-to-charge ratio The mass-to-charge ratio (''m''/''Q'') is a physical quantity relating the ''mass'' (quantity of matter) and the ''electric charge'' of a given particle, expressed in units of kilograms per coulomb (kg/C). It is most widely used in the electrody ...

, using opposing electrical and centrifugal forces. This allows the classifier to select particles of a specified mass-to-charge ratio independent of particle shape. Further work on the technique used centrifugal and electrostatic forces to classify particles according to their mass-to-charge ratio.

References

{{Reflist Measuring instruments Scientific instruments Scientific techniques Aerosol measurement