... carving process, electroplating wastewater, printing and dyeing, electronic semiconductor, chemical, pharmaceutical, etcFeatures:1.High impedance preamplifier, strong ability of anti ... optical coupling isolation output technology4.LCD digital indicator with back light5.With upper and lower limit alarm, 2 separate 220VAC/3A relay ... 96*125mm13.N.W: 1 KG Anjun ph indicator controller with High Quality