CHARACTERIZATION OF AGGLOMERATED AND AGGREGATED AEROSOL-PARTICLES USING IMAGE-ANALYSIS

Accurate particle size characterization of aggregated and agglomerated particles is only possible by analysis of photographs. Both the prima ry particle size and the morphology of the aggregate are important exp erimental results. Since standard image analysis techniques for partic le size analysis usually recognize only single particles, a new progra mme, called here Sparse Hough Transformation, was developed for the au tomated recognition of spherical particles within an aggregate. The me thod is shown to perform well, even for images with many overlapping p articles. The structure of the aggregate is analysed using the fractal dimension, determined from the density-density correlation function. Finite size effects, important when dealing with aggregates containing few primary particles, are taken into account by including a cut-off function.