2-in-1 pH TDS Water Quality Tester Monitor Replaceable pH Electrode Range : pH: 0.00~14.00pH / TDS: 0.00~19.99ppt Resolution : pH: 0.01pH / TDS: 0.01ppt Accuracy : pH: 0.1pH / TDS: 2%FS Temperature Compensation: 0~50C / Operating Temperature: 0~50C This meter is a very useful tool for environmental monitoring, laboratories, hydroponics, aquariums, swimming pools, spas and food processing etc