Abstract: A specific gravity control apparatus 200 is disclosed which uses a plurality of electrodes 202, 204 and 206 to measure the height of a control liquid within a leg 8 to provide enhanced control of the specific gravity of the solution S. In a specific gravity control apparatus 250, a flexible diaphragm 254 isolates the solution from a control fluid. This permits a nonconductive solution to be maintained at a specific gravity by the apparatus using at least one electrode to measure the level of the control liquid which can be conductive.

Abstract: A solvent recovery system (10) is disclosed which separates material from a solution by refrigeration. The solution is used to wash a printing plate and the material is washed from the plate by the solution. The contaminated solution is refrigerated within a disposable container (32) to separate the material from a solution. The purified solution is then drawn off from the container, leaving the material as residue for disposal in the container.

Abstract: A viscosity control (10, 200) is disclosed which employs a turbine flow meter (52). A pump (18) provides for a flow of solution through a conduit at a relatively constant pressure. The flow rate of the solution through the conduit thus varies depending on the viscosity of the solution. The turbine of the flow meter rotates at an angular velocity related to the flow rate. The rotational velocity of the turbine is sensed. When the turbine speed decreases as viscosity increases to a set maximum viscosity, the control supplies solvent to the solution to decrease the viscosity.