Droplet size determination by laser light scattering

Product delivery by spray has become increasingly important to the pharmaceutical, cosmetic, paint, fuel injector and agricultural industries. Droplet size is a key parameter in spray performance evaluation and nozzle design optimization. The current paper will illustrate how laser light scattering is used to characterize droplet size distributions in sprays. This is not a trivial matter since sprays often are highly concentrated, occupy large areas and may be pulsed at short frequencies. Thus the laser scattering instrument has to be able to cope with multiple scattering and provide rapid data acquisition. The method provides size resolution in the range from 0.5 - 850 micrometer at concentration levels up to 95 % light obscuration. Data may be acquired up to 2500 Hz.