Device and method for optically detecting the presence of ingredients of a pourable product

A device for optical determination of ingredients of a pourable product, in which the product, as a stream in a conduit, passes a measurement window (6), for analysis by means of a spectrometer (1) with a predetermined measurement duration for performing the analysis,

• wherein the stream at the measurement window (6) has a flow direction with a component in the direction of gravity;
• a valve (8) with an open position and a closed position is disposed downstream of the measurement window (6) in the conduit;
• a controller is provided, which is embodied to move the valve into its closed position at least for the duration of the measurement:
• the conduit, in the region of the measurement window, is embodied as a movable container (2) with side walls (13, 14, 15), and a drive (5) is provided for generating a vibrating motion of the container;
• the motion of the container (2) has a directional component which differs from the direction of the normal to the measurement window face.