Development and Performance Test of Unipolar Diffusion Charger for Real-time measurement of the Submicron Aerosol

摘要

We designed and evaluated a unipolar diffusion charger, which consisted of corona discharge, mixing, and ion trap zones. For the performance evaluation of the diffusion charger, the sodium chloride (NaCl) with size range of below 0.1μm, and the dioctyl sebacate (DOS) particles with size range of 0.1 to 0.8μm, were used. The diffusion charger was evaluated in parameters of the particle loss and the charging efficiency which is the product of penetration by the number of chargers (P·n). The particle loss was below 15% and charging efficiency had a good linearity in different particle diameters. Finally, we have estimated the mean diameter of the generated submicron particles by using the diffusion charger, CPC (condensation particle counter, TSI 3025A), and an aerosol electrometer (TSI 3068A). Even if estimated size distributions have some errors, but after calibration it can be used for real-time measurements.