This PH meter can be used to test pure water production and consumption, plating solution, boiler water, the fish tank, industrial waste water, swimming pool, photographic rinses, well water, deep well water, laboratory, aquaculture, food processing, family, office, physical and chemical teaching, ionized water, travel health, municipal water supply, cosmetics, human urine PH value, etc.PH pen measuring range is 0 to 14, 7 above is alkaline, household water basic present neutral (7), after the water purifier filter should be weakly acidic water . Measuring pH Range: 0.0 - 14.0 pH Resolution: 0.1 pH Accuracy: ±0.1 pH (20°C), ±0.2 pH Operating Temperature: 0 - 50°C (32 - 122°F) Calibration: manual,1 point 1 x Digital pH meter 1 x Manual 1 x Calibration buffer solution