Chemiluminescence Nox Analyzer

The signal begins when nitric oxide reacts with ozone and produces nitrogen dioxide in an excited energy state. As the excited molecules return to a lower-energy state, they emit light. Because the emitted light intensity is proportional to the nitric oxide concentration, the measured signal provides a basis for quantifying NO in the sampled gas and tracking changes in its level.

Nitrogen dioxide is commonly converted to nitric oxide before the measurement when the goal is total NOx rather than NO alone. The analyzer can then use the same ozone-driven light-producing reaction for the converted nitrogen dioxide and the original nitric oxide. This approach allows the combined nitrogen oxide content to be assessed instead of only the directly measured NO fraction.

Direct measurement focuses on nitric oxide already present in the gas, using the light produced by its reaction with ozone. Total NOx assessment also accounts for nitrogen dioxide by converting it to nitric oxide before measurement. Comparing these measurement modes helps distinguish the NO portion from the combined NO and NO2 content in an environmental or emissions sample.

A proportional relationship between emitted light intensity and nitric oxide concentration makes the optical signal useful for quantitative analysis. Changes in gas composition therefore produce corresponding changes in the measured light. This relationship supports comparisons among air-quality samples, industrial emissions, and combustion experiments, where researchers need to evaluate nitrogen oxide levels or changes associated with pollution-control technologies.

For NO measurement, the sampled gas is brought into the ozone-based reaction so the resulting light can be related to nitric oxide concentration. When total NOx is required, nitrogen dioxide is first converted to nitric oxide, after which the combined amount enters the same measurement principle. The selected sequence determines whether the result represents NO alone or total NOx.

The analyzer is useful when researchers need nitrogen oxide measurements for air-quality assessment, industrial emissions testing, or combustion research. It also supports evaluation of pollution-control technologies by showing nitrogen oxide levels associated with a process or treatment. These applications connect the instrument's chemical measurement principle with environmental monitoring and efforts to characterize or control emissions.