Method of monitoring ink-water balance on a lithographic printing press

摘要

In a lithographic printing system, a light source and a plurality of photodetectors are used to monitor the amount of fountain solution interacting with the ink. The light source irradiates an ink form roller and the photodetectors are disposed at a specular angle and at one or more non-specular angles to monitor the reflected light. An electronic circuit is responsive to the output of the photodetectors and is used for providing an indication of the amount of fountain solution emulsified in the ink, and lying on the surface of the ink.