PHscan10S pocket pH tester is equipped with a standard pH   electrode (Round glass bulb) that used to measure the pH of    non-viscous, non-high temperature liquids, e.g., wastewater,   tap water, drinking water, rainwater, etc.   Features: 2 points push-button calibration with auto-buffer recognition. Hold function freezes the current displayed value for easy viewing. Auto-power off feature helps you effectively conserve battery life. Replaceable electrode reduces maintenance and replacement cost. Waterproof feature to ensure complete protection in harsh     environments.