Prior to withdrawing water for use, it is recom-mended that you allow some water to run todrain to rinse up the system. If using a resistivitymeter, the display will register a gradualimprovement of water quality.Resistivity Meter/PuraliteThe resistivity measurement in the dual holderB-pure is accomplished with an in-line digitalreadout meter and integral cell. The resistivitymeter measures the specific resistance of thewater on a scale of 0.1 to 18.3 megohm-cm.The resistivity measurement is automaticallytemperature compensated to 25°C regardless ofsystem water temperature.Other systems may include a Puralite. Theselights are go/no-go indicators. The light will illu-minate green when the purity of the water exit-ing the system is above the value of the individ-ual light. When the purity drops below thatvalue, it will illuminate red, indicating the needfor cartridge replacement.14Operation