Method for measuring layer thickness in printing machines

摘要

The invention relates to a method for measuring layer thickness, in particular for the dynamic measurement of damping water layer thickness in printing presses. The aim of the invention consists in providing a method for measuring layer thickness which permits a higher sensitivity of measurement. It is the object of the invention to configure the method in such a way that changes in layer thickness influence the output signal of the measuring device more strongly. This object is achieved by using a beam splitter to split the beam emitted by the light source into at least two parts and directing them in different directions, detecting at least a part of the split beam directly by a first sensor and guiding at least a further part of the beam onto the prescribed measurement location and converting the light reflected from the measurement location by at least one second sensor into an electrical output signal, which output signal of the second sensor is used to control the light source, and using the signal of the first sensor as a measure of the layer thickness. <IMAGE>