Dr Labs pH-030 New Arrival with Precision Glass Bulb Electrode Portable PH Meter Liquid PH Alkalinity Value Digital Water Purity Tester Hydro tester Pen with Care Box & Calibration Screw Driver Suitable for Household RO Water Purifiers Filters, Drinking Water, Swimming Pools, Spas, Food, Drink, Gardening, Aquariums, Hydroponics A pH meter, also called a sensor or tester, is a device used to measure the alkalinity of a substance with a single-line LCD screen, a replaceable electrode, and a low power demand. A pH meter used to measure the pH of substance such as water, food, beer, or wine in laboratory, industrial, and food applications.