A Particle mass analyser (PMA) is an instrument for classifying aerosol 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]
It one of the three types of monodisperse aerosol classifier, the others being the differential mobility analyser (DMA, for electrical mobility size), and the aerodynamic aerosol classifier (AAC, for relaxation time, or aerodynamic diameter). The corresponding three quantities are related by the expression τ = mB, where τ is relaxation time, m is mass and B is mobility.
Further work improved the technique by engineering the centrifugal force to match the electrostatic force across the whole classification region, thus increasing the throughput.[2]
References
edit- ^ Ehara; et al. (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. Bibcode:1996JAerS..27..217E. doi:10.1016/0021-8502(95)00562-5.
- ^ Olfert and Collings (Nov 2005). "New method for particle mass classification—the Couette centrifugal particle mass analyzer". Journal of Aerosol Science. 36 (11): 1336. Bibcode:2005JAerS..36.1338O. doi:10.1016/j.jaerosci.2005.03.006.