optical particle sizers

SIMULTANEOUS OPTICAL MEASUREMENT OF PARTICLE SIZE AND SHAPE Bernhard Michel, Scientific Consulting, Am Steinbruch 1, D-91126 Rednitzhembach, Germany Wolfgang Mutter, Fritsch GmbH, Industriestrasse 8, D-55743 Idar-Oberstein, Germany Abstract. Conventional optical particle sizers evaluate the dependence of scattered light on the polar angle (angle relative to the optical axis) in order to determine size distributions of particles. The dependence on the azimuth angle (around the optical axis) commonly is not considered, although it contains valuable information about particle shape. We present a novel optical particle analyzer developed by Fritsch GmbH, which is based on an inverse Fourier setup. It uses a custom-made silicon sensor to detect the dependence of the scattered light on both polar and azimuth angle, thus enabling the simultaneous determination of particle size and shape. The particle shape analysis is currently restricted to the Fraunhofer regime, starting with a minimum size of 3 μm. For the particle size measurement, small- and wide-angle light scattering is evaluated, leading to a possible dynamic range from 10 nm up to 2 mm. The main advantages of the new particle analyzer are its cost-efficiency, because it is an all-in-one solution,