Abstract: A method for detecting Raman scattered light using at least one interference filter and a detection unit, the Raman scattered light to be detected including an incoming scattered light signal, wherein the method includes the following steps: * a first filtered scattered light signal is generated by the application of a first transmission function to the incoming scattered light signal, the first transmission function being assigned to a first optical path length L1 through a first interference filter, and the first transmission function defining a first spectral band ??1; * a second filtered scattered light signal is generated by the application of a second transmission function to the incoming scattered light signal, the second transmission function being assigned to a second optical path length L2?L1 through the first interference filter or through a second interference filter, and second transmission function defining a second spectral band ??2; and * the first and the second filtered scattered light signa

Abstract: In determining the size of particles in a flowing sample, initially scattered light is detected on a detector, in the form of images, standardization of the measured images takes place and determination of an offset and of an angle of rotation at least of a partial region of two temporally successive images relative to each other is effected. Two images congruent are subdivided into many partial areas with respectively a specific number of pixels and averaging of the brightness values of each individual partial area is implemented. Subsequently, the average brightness value of a partial area of the first image is correlated with the average brightness value of the partial area made congruent with this partial area in the second image (cross-correlation between the images). For each pair of congruent partial areas of the images, a correlation value is thereby produced.