... to measuring pH, Oxidation-Reduction Potential and ion concentration. :: Ion concentration mode directly displays readings in ppm,ppt ... 16.000pH pH Accuracy±0.002pH Resolution0.001pH Ion Concentration Range0~19999ppm Ion Concentration Accuracy±0.5% (Monovalent), ±1 ... data sets with Date/Time stamping OutputUSB communication interface Power RequirementsDC9V, using AC adapters, 220VAC, 50Hz Dimensions210( ...