A method for determining the thickness distribution of a damping solution film on a printing plate of an offset printing press

摘要

The thickness of the dampening film on the top of the printing plate is determined by adding a fluorescence to the film. The film is then subjected to radiation by long wave ultraviolet rays which excites the fluorescence, whereby radiation from it can be taken as a dimension of the film thickness. The fluorescent radiation is measured by a light strength measurement appts. in the form of a photomultiplier. Pref. the determination of the film thickness takes place in the hydrophilic region fo the plate, i.e. in the area where there are no colours. ADVANTAGE - Safe to humans.