... 3.Temperature compensation 4. Drinking water,Swimming pool and Tap water PH controller/PH meter/PH electrode ... water treatment, glass carving process, electroplating wastewater, printing and dyeing, electronic semiconductor, chemical, pharmaceutical, etcFeatures:1.High impedance preamplifier, ... .LCD digital indicator with back light5.With upper and lower limit alarm, 2 separate 220VAC/3A relay ...