Device and method for optical measurement

A device for optical measuring of small particles, such as grains from cereals and like crops, for analysis of the quality of the particles, which comprises

• a sample-feeding carrier which is adapted to take up particle samples, which each comprise at least one particle, in sample holders and transport the particle samples to a place for optical measurement,
• a mirror-supporting means which follows the movement of the carrier and has a mirror for each sample holder,
• a device for illuminating a particle sample when this is positioned for optical measurement, and
• a detector which is sensitive to electromagnetic radiation for recording at least one result of an optical measurement of the illuminated particle sample,
• a mirror in the mirror-supporting means reflecting the particle sample so that a mirror image of the particle sample stands essentially still seen from the detector, when the measurement is being recorded, owing to the fact that the mirror image of the particle sample falls on a center axis of the movement of the mirror-supporting means.