In-situ Aerodynamic Sizing of Aerosol Particles with the Spart Analyzer

摘要

A single particle aerodynamic relaxation time (SPART) analyzer has been developed to measure the aerodynamic size distribution of aerosol particulates in the range 0.1 to 10.0 micrometer in diameter. The analyzer sizes and counts individual suspended particles and droplets from sampled aerosols, determines their aerodynamic diameter, and generates the size distribution in real-time. The measurement is independent of the electrical and optical properties of the particles. The size range and resolution of the SPART analyzer depend on the acoustic frequency. Operating at 27 kHz, the instrument's effective sampling rate was calibrated in the range of 0.3 to 6.0 pm using test aerosols containing monodisperse polystyrene latex spheres (PLS) and olive oil droplets. The instrument can count and size aerosol particulates at a maximum rate of 200 particles/sec. The sensing volume of the instrument is approximately .00001 cc, which allows the size distribution measurement of an aerosol containing a relatively high particulate concentration without an appreciable coincidence loss.