The BL983317 is a compact, panel mounted, process controller for measuring conductivity of a process stream. The device features a large LCD with protective cover. Users may choose from automatic or manual dosing modes. When in automatic mode the dry contact relay is activated when a reading is below the set point. The relay can be used to activate a dosing pump to add chemical until the desired set point is reached. Chemicals that can be dosed include nutrient solutions.
The BL983327 is a closely related product that has the same measurement range but has a relay that is activated when the reading is above the set point.