Thermolyne NANOpure DIamond Analytical ultra pure water system. This water purification system is designed to provide high resistivity, reagent grade water that exceeds ASTM Type I, CAP and NCCLS Type I standards. It uses a four-stage deionization process and a 0.2   
micron filter to polish suitable feed water (distilled, deionized, or reverse osmosis) to produce water with a resistivity of up to 18.2 megohm-cm. Water resistivity is continuously   
monitored by a resistivity cell and displayed on a digital display.   
   
The electronics can be verified and calibrated utilizing a N.I.S.T. Traceable Calibration module.