Rozway pH Meter with Backlight [.01 pH Resolution] Rozway pH Meter with backlight. Range: 0-14.0 pH. Resolution: 0.01. You can use a pH meter to check the pH of your water, mash, [test Star San effectiveness] and finished beer. Digital Pocket Size PH Meter/PH Tester/Water Quality Tester for Drinking Water, Hydroponics, Aquariums, Pools, Beer, Wine, Food, 0.01 PH Measurement – Extra PH Test Calibration Solution Pack More: Recent Amazon Finds