... :: Calibrate up to 3 points for pH using USA or NIST buffer sets; Up to 5 points ... ORP Electrode, pH Standard Buffer, Temperature Probe, Power Adapters, Electrode Holder ModelLDR-930 pH Range-2.000~ ... NIST, pH4.00/6.86/9.18 or USA, pH4.01/7.00/10.01 Ion Calibration ... Date/Time stamping OutputUSB communication interface Power RequirementsDC9V, using AC adapters, 220VAC, 50Hz Dimensions210(L)×188(W)×60(H ...