The Comparison of Laser Diffraction, PDA and Photogrammetry for Aerosol Measurement

Optical methods are established as a standard tool for aerosol size measurement. The aim of this paper is to compare the results of two commercial optical instruments based on the phase-Doppler anemometry (PDA) and laser diffraction (LD) with the inhouse optical photogrammetric measurement method. For the purpose of this measurement, a new inhouse image processing procedure was developed with the use of MATLAB script. The accuracy of this method was tested on several calibration particle samples with a sufficient agreement with the PDA and LD commercial instruments. Subsequently, the water droplet distributions of a two-phase nozzle were evaluated by all three methods. The knowledge of the detailed droplet size distribution of the nozzle is then to be used for the development of a new facility for the study of heterogeneous droplet nucleation. Moreover, these results are useful for determining the advantages and disadvantages of these methods for their application in the wider field of aerosol technology.