Zur Bestimmung derKonzentration und Größe vonPartikeleinschlüssen in Tropfen

Abstract

A measuring method to estimate the size and the concentration of monodisperse, spherical latex particles will be introduces. The method enables the unique characterization of mean values in view of process engineering tasks. For the generation of monodisperse droplets, a drop-on-demand droplet generator system is developed and produced. A PC based electronic device drives a piezoelectric droplet generator and enables the generation of very small water droplets below 10 micrometer. An optical measurement setup measures the scattering response of suspension droplets in the size range of 80 to 100 micrometer in diameter. The data have to be pre-processed by a filtering algorithm. Therefore, an automatic size determination algorithm determines the diameter of the droplets and afterwards, a calculation of the Mie scattering is used to remove the scattering response caused by the water droplets. The remaining scattering information about the inclusions are analysed by a wavelet transformation and a speckle evaluation, and the intensity ratio in forward direction referred to the complete measured scattering light is calcuated. Only by using these three parameters the estimation of concentration and size of the inclusions is possible.