The standard applies to measurements in flue and exhaust gases at NO concentrations between 10 and 5000 cm3/m3. Note Many instruments for the determination of NO using chemiluminescence are suitable for measurement at lower concentrations. Due to the typical concentrations in exhaust gases, as well as the availability of calibration gases, the concentration range in this standard is limited. In instruments equipped with a converter for the conversion of nitrogen dioxide (NO2) into nitrogen monoxide (NO), the total content of nitrogen oxides (NOx = NO + NO2) can also be determined by this method. The inaccuracy of the method of determining the total nitrogen oxide content fluctuates and is too great for certain applications. For the sake of completeness, the determination of the total nitrogen oxide content is dis ussed in the appendix.
NEN 2039-1979 history
1979NEN 2039-1979 Air quality - Smoke and exhaust gases - Determination of nitrogen monoxide by chemiluminescence