... from industrial boiler, industrial furnace, power plant boiler flue. 4. Provides parameters of flue gas temperature, humidity , pressure, velocity ... values.3.10 Function of reports printing 4. Calibration and Back Flushing4.1 Manual calibrating zero and calibration of SO2, ... of SO2, NOx, O2 measuring device.4.3 Timing automatic calibration4.4 Function of calibration start time and calibration ...