... back light 3.Temperature compensation 4 water ph sensor ApplicationIndustrial waste water,pure water, circulating water, ... glass carving process, electroplating wastewater, printing and dyeing, electronic semiconductor, chemical, pharmaceutical, etcFeatures:1.High impedance preamplifier, ... ~+1999mV3.Signal output: 4.00~20.00mA4.Operation: -10~+60degree;0~95% relative humidity, no condensing5.Storage: ...