Serinus Gas Analyzer

Properties of Nitrogen Oxides gases

Nitrogen Oxides (NOX) is the product of endothermic reactions within combustion engines and causes significant environmental pollution. The main source of Nitrogen Oxides is from the engine of automobiles and these pollutants are harmful to humans in their respective forms or in the creation of ozone (O3) or acid rain. Nitrogen Oxides are most prevalent in our societies as a contributor to asthmatic conditions as well as the smog found throughout many industrialized cities.

Nitrogen Oxides measurement theory

The measurement of the Nitrogen Oxides is performed via the gas phase chemiluminescence method. The Serinus 40 NOx analyzer follows these principles and measurement techniques:
Sample air is drawn into the reaction cell via two separate (alternating) channels the NO and NOX. The NO_X channel travels through a delay coil enabling the same sample of air to be sampled for NO, NO₂ and NO_X.

• The NOX channel passes through an NO₂ to NO converter, NO₂ is converted to NO
• Sample air (NO & NO_X channels) enter the measurement cell where NO reacts with Ozone in the following reaction

• This reaction releases energy in the form of chemiluminescence radiation (1100nm), which is filtered by the optical bandpass filter and detected by the photomultiplier tube (PMT)
• The level of chemiluminescence detected is directly proportionally to the NO in sample
• NO2 is calculated by subtracting the NO measurement from NOX measurement

Nitrogen Oxides gas analyzer measurement

The Serinus 40 Nitrogen Oxides analyzer uses gas phase chemilluminescence detection to perform continuous analysis of nitric oxide (NO), total nitrogen oxides (NOX), and nitrogen dioxide (NO2). The Serinus 40 NOx analyzer measures to a sensitivity of 0.4ppb in the range of 0-20ppm. The measurement of these three gases is performed with the following main sub-components: NO2 to NO converter Delay coil (NOX channel) Ozone source with reaction chamber (NO + O3) Photomultiplier Tube (PMT) Calculation of NO2 from NO/NOX

The concentrations are automatically corrected for gas temperature and pressure changes and referenced to 0°C, 20°C or 25°C at 1 atmosphere. This allows the Serinus 40 nitrogen oxide analyzer to sample in the most useful measurement range for NO, NO₂ and NO_X.