Measurement of mass of aerosol particles

properties of the aerosol particles is needed. [1] Among these properties, particle size (particle diameter, if the particle in question is spherical) is an especially important quantity to be measured, because it significantly affects many of the aerosol-related phenomena. Aerosol particles are, however, often non-spherical, and a geometric diameter cannot be defined unequivocally for them; instead, several kinds of effective diameters are defined and measured. On the other hand, particle mass is a quantity inherent to each individual particle: it is uniquely defined even for a non-spherical particle. It is a direct measure of the amount of substance contained in an individual particle, and has crucial effects on particle motion and other physical phenomena; hence it should be no less important than the particle size. Until recently, however, there has been no established method for An aerosol particle mass analyzer (APM) which classifies aerosol particles according to their mass has been developed. Mass distributions of aerosol particles are measured by the APM combined with a particle counting device. Particle masses can be measured in the range 3 × 10 -18 g to 2 × 10 -12 g, which partially fills the mass range that has not been covered by existing mass measuring instruments such as mass spectrometers and conventional balances. The invention of the APM has led to a variety of new techniques for evaluating aerosol particle properties such as effective density, material density, porosity, fractal dimension, and mass concentration of suspended particulates, among others. This article describes the principle of the APM, its features differentiating it from other instruments for classifying aerosol particles, and its applications to characterization of aerosol particles. The significance of measurement of particle mass in aerosol science, and the historical process that has led to commercialization of the APM are also described from the viewpoint of “synthesiology.”