Electrostatic Precipitator for the Collection of Aerosol Samples for Particle Size Analysis

摘要

An electrostatic precipitator has been described with which a sample suitable for particle size analysis can be collected from a few cubic centimeters of air. It operates at a volumetric flow rate of 5 cm3/min. equivalent to a linear velocity of 4-5 cm/sec. The entire sample is deposited in a small area on a single electron microscope grid. The ions needed for charging the aerosol particles are provided by the ionization of air molecules by beta particles from a tritium source. The precipitating electrostatic field is provided by a 2,1OO-volt battery pack. A marked segregation of particles with respect to size makes it necessary to obtain a series of electron micrographs of the sample. However, when the electrostatic precipitator was used simultaneously with a thermal precipitator to sample the same aerosol, the particle size distribution parameters estimated by the two different methods were in good agreement.