Abstract: A filtration system comprising a reverse osmosis unit having an inlet thereto, a permeate outlet and a concentrate outlet wherein a first conduit extends from a source upstream of the reverse osmosis unit to the liquid inlet, a second conduit extends from the concentrate outlet wherein a flow control mechanism controls the amount of concentrate flow to the third and fourth conduits, the third conduit being connected to the first conduit while a conductivity sensor on the first conduit is mounted downstream of a point where the third conduit connects to the first conduit, the conductivity sensor being connected to the flow control mechanism to control the amounts of concentrate which are directed to the third and fourth conduits in accordance with the conductivity of the liquid. The arrangement allows one to approximate a measure of the total dissolved solid and thereby maximize the efficiency of the system and avoid unnecessary dumping of liquid to a drain.

Abstract: A system for metering the volume of a liquid, e.g. ink, supplied by a positive displacement pump to an installation, such as a printing press, employs a device for generating a first series of signals each indicative of completion of a pumping stroke. The speed of the pump is also sensed to generate a second series of signals each indicative of the positive supply of liquid by the pump. The signals of the first series are counted only in the presence of a corresponding signal of the second series. The result is an accurate numerical indication of the total volume of liquid pumped.

Abstract: A system for metering the volume of a liquid, e.g. ink, supplied by a positive displacement pump to an installation, such as a printing press, employs a device for generating a first series of signals each indicative of completion of a pumping stroke. The speed of the pump is also sensed to generate a second series of signals each indicative of the positive supply of liquid by the pump. The signals of the first series are counted only in the presence of a corresponding signal of the second series. The result is an accurate numerical indication of the total volume of liquid pumped.