Oxygen analyzer with enhanced calibration and blow-back

摘要

A combustion gas analyzer for measuring the concentration of a gas constituent in an exhaust gas stream is provided. The gas analyzer includes a sensor cell assembly coupled to a transmitter having electrical circuitry configured to provide an output of the concentration of the gas constituent as sensed by the sensor cell assembly. The combustion gas analyzer also includes a filter substantially enclosing the sensor cell assembly and a conduit coupled to the filter at a first end of the conduit and coupled to a valve assembly at a second end of the conduit. The conduit is used for supplying a calibration gas to the sensor cell assembly or for supplying a blow-back gas used to purge the filter.