Optical sensor system on a device for the treatment of liquids

An optical sensor system on a device for the treatment of liquids comprising:

• at least one device for the projecting (9, 10, 11) of light in the direction of an optical axis (4) onto at least one illumination area (12) in a space,
• an adjustment device (31) for adjusting the relative position of the at least one illumination area and a boundary surface in a direction diagonal to the optical axis,
• an adjustment device (32) for adjusting the relative position of the at least one illumination area and the boundary surface in the direction of the optical axis,
• a processing unit (21) for controlling the adjustment devices so that the optical axis corresponds with a basic arrangement of the projection axis at the beginning of a scanning operation and in the course of the scanning operation simultaneously adjust the relative position of the at least one illumination area and the boundary surface diagonal to the optical axis and in the direction of the optical axis,
• at least one apparatus (11) for the imaging of the at least one illumination area during the adjustment of its relative position, the at least one apparatus including at least one photodetector (13), the at least one photodetector (13) providing at least one measurement signal, and
• the processing unit (21) connected with the at least one photodetector (13) for evaluating the at least one measurement signal.