DEVICE FOR ASCERTAINING AND/OR KEEPING THE MIXING RATIO OF A LIQUID MIXTURE CONSTANT

摘要

In the case of an apparatus for ascertaining and keeping constant the concentration of alcohol in the plate dampening fluid used in an offset litho press, having a float vessel with an inlet and an overflow such that the float controls the supply of alcohol in accordance with its level relative to the fluid, a high degree of accuracy and a simple possibility of displaying and storing the concentration data is made possible by having a marker mounted on the float and having a vertical scale of zones marked thereon which may be sensed without mechanical contact by a sensing device at a fixed height. Furthermore the sensing device has a control signal output connected with a controller which is furthermore acted upon by a set point signal and has at least one output signal connection for controlling a valve regulating the supply of alcohol to said fluid.