# Astronomy:Particle mass analyser

Particle mass analyser is a measurement technique for classifying aerosol 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 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, using opposing electrical and centrifugal forces. This allows the classifier to select particles of a specified mass-to-charge ratio independent of particle shape.[1]

Further work on the technique used centrifugal and electrostatic forces to classify particles according to their mass-to-charge ratio.[2]

## References

1. Ehara (March 1996). "Novel method to classify aerosol particles according to their mass-to-charge ratio - Aerosol particle mass analyser". Journal of Aerosol Science 27 (2): 217. doi:10.1016/0021-8502(95)00562-5. Bibcode1996JAerS..27..217E.
2. Olfert and Collings (Nov 2005). "New method for particle mass classification—the Couette centrifugal particle mass analyzer". Journal of Aerosol Science 36 (11): 1336. doi:10.1016/j.jaerosci.2005.03.006. Bibcode2005JAerS..36.1338O.