How does the CA-6200 Series Combustion Analyzers compensate for cross sensitivity of NO2 on the SO2 Sensor?
When the SO2 and the NO sensors are installed, the same estimated value of NO2 that is used to calculate NOx is also used to compensate for the effect NO2 has on the SO2 sensor. If NO2 were to exceed this estimated value and the SO2 measurement totals, the SO2 reads negative and an alarm message is displayed. When both the SO2 and the NO2 sensors are installed, the measured NO2 concentration is used to compensate for the effect NO2 has on the SO2 sensor. This provides the most accurate measurement of SO2. A couple of important notes: • If there is not any sulfur in the fuel (de-sulfured fuel), there will not be any SO2 in the flue. • The type of fuel and the type of system will give some indication whether to expect NO2 to be greater than the estimated value when only NO is measured. The CA-6200 Combustion Analyzers recognize the sensors installed and automatically reconfigure the calculations based on the installed sensors. This makes it possible, for example, to reconfigure a model i
