Polymetron analyzers are designed for ease of installation and use, requiring only power connection and sample hydraulics. It is fitted with a quick-loop valve at the bottom of the analyzer, a constant head vessel and minimum sample flow detection to allow for variations in sample pressure, flow, and distance from the analyzer to the fresh-sample point. The principle of operation is that of ion selective electrode measurement after pH conditioning. Sample pH conditioning is essential for limiting the interference of temperature or other ions. Constant buffering is assured using regulated reagent addition across ambient and sample temperature changes.