Abstract: A fluid monitoring and control apparatus and method including providing a programmable and reprogrammable control unit comprising a display, user inputs, and input/output connections; placing a programmable logic controller in direct communication with the control unit, which programmable logic controller is programmable and reprogrammable through the control unit; and placing a plurality of fluid parameter sensors in direct communication with the control unit. The invention is also of a fluid control apparatus and method comprising providing a membrane and estimating salt rejection by the membrane.

Abstract: A fluid treatment apparatus (100) and method having a variety of interchangeable input/output cards (10) capable of communicating with a variety of parameters including analytical parameters. A programmable central processing unit (124), input/output cards (10), data bus (30), display (102), and keypad (104) are integrated into a single integrated apparatus (100). Analytical parameters are received directly by the appropriate input/output cards for direct communication with the central processing unit (124). The central processing unit also outputs control parameters through the input/output cards.

Abstract: An apparatus for monitoring particulates in a liquid stream and the rate at which the particulates foul a filtering medium, generally a reverse osmosis membrane, to determine at what point in time the filtering medium should be cleaned or replaced. The apparatus includes a monitoring filter unit having a plurality of filter portions. The pressure drop across each filter portion, through which a sample of the feed stream is passed, is monitored. Fouling of a filter portion by accumulated particulate thereon causes an increase in the pressure drop across the filter unit. The increasing pressure drop is monitored as an indicator of the correlative or correspondent fouling of the main filtering medium to be protected. Different filter portions in the filter unit are successively used as each becomes fouled, allowing continuous monitoring for extended periods of time between filter media changes in monitoring filter unit.