Waterproof tester, 3 ranges: 0 – 199.9 µS/cm, 200 – 1999 µS/cm and 2.00 – 20.00 mS/cm, resolution 0.1 µS/cm, 1 µS/cm and 1 mS/cm, microprocessor controlled, large display with simultaneous temperature display, automatic temperature compensation (ATC), 3 point calibration, user-replaceable sensor.