Device for the detection of condensation on the inner and outer sides of windows

A first bunching hologram (2) and a second bunching hologram (3) together represent a combinational hologram (CH) (1) and act as a defined deflector device for electromagnetic measured radiation that is directed at the CH in a vertical direction. The CH helps identify a coating of rain or deposited film on the outside or inside of a motor vehicle windscreen/window. Independent claims are also included for the following: (a) A sensor for measuring coatings on inner/outer sides of motor vehicle windscreens/windows; (b) and for a windscreen/window with deflector device.