Milwaukee C66 Waterproof Conductivity EC/Temp Tester with Replaceable Electrode, 0.00 to 10.00 microSiemens/cm, 0.01 microSiemens/cm Resolution, +/-0.2 percent Accuracy Portable, waterproof conductivity meter suitable for heavy-duty applications such as wastewater treatment and agriculture Automatic temperature compensation, manual one-point calibration Automatic shutoff for low battery prevents erroneous readings