Investigation into the information of colour and polarization of scattered light applied to particle control of ampoules

In order to automatically control the quality of liquid filled ampoules, several systems are available on the market, which detect the scattered light from moving particles using a CCD-camera. This detection method already was subject of measurement investigations with reference particles. In this work the exact physical solution of the scattered light from small spheres is calculated numerically and the information on colour and polarization are investigated. These calculations confirm the results of the former measurement investigation and show the optimal measuring configuration. The use of monochromatic light has to be abandoned and a polarization filter cannot give a general improvement for different particle sizes. Also particles and air bubbles can be distinguished better only outside the interesting particle size area. These conclusions can be transferred to any particle forms. Therefore an observation from forward direction is preferable rather than from side direction