The choice, design and performance of a multichannel aerosol particle counter

Abstract A discussion of currently available automated particle counting techniques precedes a description of the design and construction of a low cost multi-channel particle counting system. The unit counts airborne spherical particles between 0–5 and 4 μm in diameter, in nine size ranges and a further channel records the total count of particles above 4 μm in diameter. The performance of this unit is discussed with reference to measurements of water and carbon tetrachloride aerosols. A feature of the unit is that other particle size ranges may be counted, using the ten available channels, provided that the unit is recalibrated with monodisperse spheres of known diameter.