Waterproof tester for pH and TDS, temperature display, pH: 0.0 – 14.0, resolution 0.1 pH, auto buffer recognition, up to 5 calibration points; TDS: 2 ranges 0 – 999 ppm and 1.00 – 10.00 ppt, resolution 1 ppm and 0.01 ppt, 2 calibration points; automatic temperature compensation (ATC), microprocessor controlled, large display