Airpointer - Nitrogen Oxides Analysis Modules
The nitric oxide (NO) molecule is quite reactive and unstable. In ambient air, it reacts with oxygen to form the toxic nitrogen dioxide (NO2).
Where does Nitrogen Oxide come from?
Nitrogen oxide is mainly an unwanted by-product of fuel combustion at high temperatures. Cars and power plants are the main sources of nitrogen oxide.
What are the effects of Nitrogen Oxide?
Nitrogen oxide causes a multitude of symptoms, primarily in the lungs but also in other organs such as the spleen and liver. Additionally, nitrogen oxide is jointly responsible for acidification and over-fertilisation of soil and water. Gaseous nitrogen oxide may become particulate ammonium nitrate. This contributes to large-scale PM (PM2.5, PM10) pollution. During the summer, nitrogen oxide and hydrocarbons cause formation of ground-level ozone and destruction of the ozone layer.
Measurement Principle: Chemiluminescence (EN14211)
Nitric oxide in sample gas reacts with ozone to form nitrogen dioxide. This reaction results in electrically excited molecules. These molecules release their excess energy by emitting photons, which are measured by a photomultiplier tube. The airpointer NOX module is equipped with a delay loop to measure NO and NO2 from the same sample.
Zero Air Supply Check and Span Point Check
Zero air supply is part of the standard equipment so that a zero point check may be carried out automatically (e.g. daily).
An internal NO2 source for a regular span point check is available as an option.
Measured Compound: Nitrogen Oxides No/No2/Nox
- EU Directive / USEPA Procedure: Chemiluminescence (EN14211)
- Measurement principle: Chemiluminescence
- Range: Dynamic, up to 20 ppm
- Zero noise: 0.2 ppb RMS
- Lower detection limit: 0.4 ppb
- Zero drift (24 hours): < 0.4 ppb
- Span drift (24 hours): +/- 1% of reading > 100 ppb
- Response time: < 60 seconds
- Precision: 1% of reading or 1 ppb (whichever is greater) @ < 500 ppb ±1% of reading >100 ppm
- Linearity: +/- 1% of reading >100ppm
- Sample flow rate: 1000 ml/min
- Weight: 12.0 kg/ 26.5 lbs