Knestel - Chemiluminescence Detector (CLD) for NOX Measurement

The project objective was to develop a device for measuring the concentration of nitrogen oxides (NO and NO_X ) in the exhaust gas of vehicles and combustion processes. The challenge here was to achieve an enormously high dynamic range with measuring ranges between 0-100 ppm and 0-3000 ppm. The detection limit was to be only a few parts-per-billion. Another challenge was to minimize the falsification of the measurement signal by interfering components, such as water and carbon dioxide. In addition, the device had to be designed for a limited installation space.