4 in 1 PH:TDS:EC:Temperature Meter PH Tester Digital Water Quality Monitor Tester for Pools Drinking Water Aquariums Lead Time: 1-3 WeeksTDS/PH/EC/thermometer 4 in 1 (with backlit) Measuring range: pH: 0.00 to 16.00 pH; TDS: 0-19990 parts per million; EC: 0-19990 mu s/cm Resolution: 0.01 ph; 1 PPM. 1 mu s/cm; 0.1 Celsius ; 0.1 Fahrenheit Accuracy: ph: – 0.01/ 0.01 ph; TDS/EC: – 2 / 2 percent; Temperature: 0.5 Celsius Battery: 3 x 1.5 V LR44 button cell (not cluding) Temperature: 0.1 to 60.0 Celsius ; 32.0 140.0 Fahrenheit Calibration: ph: three automatic calibration (6.86 and 4.00 and 9.18 ph), TDS: 1413 mu s/cm, EC: 1413 mu s/cm Automatic shutdown: 5 minutes