Nitrogen oxides (NOx) (= nitrogen oxide (NO) + nitrogen dioxide) monitor based on an hydrogen-atom direct chemiluminescence method

Evaluation of NOx Flue Gas Analyzers for Accuracy and Their Applicability for Low-Concentration Measurements

“…It instead relies on the reaction of NO and NO 2 with H 2 that has been generated through electrical discharge. 9 It is likely that interference and mechanical complexity caused this technique to fail in commercial applications. Yet another approach involves IR absorbance.…”

Generalized response of chemiluminescence analyzers

“…(16b) also holds, the low-pressure limit is identical to Eq. (17). Thus the plug-flow and exponential dilution curves differ in Figs.…”

“…If interfering chemiluminescence is produced by the reaction of the reagent R with molecules other than D in the sample, then it is possible to discriminate against this unwanted CL if the producing reaction is slow kinetically. Equation (17) indicates that at low [M] the response is proportional to k E, so a low concentration of a reactive species may be detected even in the presence of a higher concentration of another, more slowly reacting species. The ability to discriminate against a slow reaction is shown by the twoheaded arrow in Fig.…”

“…If reaction I is pressure-dependent, then k E [M] replaces k E in Eqs. (13) and (17), and the response varies as [M f in the low-pressure limit. In this case Eq.…”