An overview of aerosol particle sensors for size distribution measurement

Fine aerosols are generally referred to airborne particles of diameter in submicron or nanometer size range. Measurement capabilities are required to gain understanding of these particle dynamics. One of the most important physical and chemical parameters is the particle size distribution. The aim of this article is to give an overview of recent development of already existing sensors for particle size distribution measurement based on electrical mobility determination. Available instruments for particle size measurement include a scanning mobility particle sizer (SMPS), an electrical aerosol spectrometer (EAS), an engine exhaust particle sizer (EEPS), a bipolar charge aerosol classifier (BCAC), a fast aerosol spectrometer (FAS) a differential mobility spectrometer (DMS), and a CMU electrical mobility spectrometer (EMS). The operating principles, as well as detailed physical characteristics of these instruments and their main components consisting of a particle charger, a mobility classifier, and a signal detector, are described. Typical measurements of aerosol from various sources by these instruments compared with an electrical low pressure impactor (ELPI) are also presented.