Waterproof Stick Type pH Electrode for Palm pH 6012WS has the built-in automatic temperature compensation via the Pt-100 sensor. The 6012ws has a pH range of 0 to 14pH and an operating temperature from 0 to 80 degrees Celsius. Extech 6012WS comes in a rugged, polycarbonate construction with a special 4-wire waterproof connector that features a glass pH sensing bulb.