Moisture prepn. device for rotary offset lithographic printer - signals impending exhaustion of additive denoted by ejection time of test dose falling below desired value

摘要

The appts. measures a flow of water into a supply container (1) by a gauge (20) while the provision of alcohol and additive according to demand is adjusted by piston pumps (21, 22). The additive pump (22) is fed from a replaceable bottle (17a). A controller (25) monitors a periodic test stroke and sounds an alarm (29) when need of replacement is shown by a magnetic reed-switch device (28) which measures the time of ejection of the test quantity of additive from the outlet (17) into the container. ADVANTAGE - High precision and user-friendliness are achieved simply.