This pocket-sized IP67- rated waterproof sensor allows you to take simple, fast, and accurate measurements. Built in sensor lets you to take measurements in two ways: you can immerse the meter tip into sample, or you can place a few drops (0.3 mL) directly on the sensor. Results are instantly displayed on the 4-digit LCD. Automatic calibration function recognizes standards, and is user selectable for either one- or two-point calibrations.