Weber, ChristianChristianWeberKapp, JohannesJohannesKappSchmitt, KatrinKatrinSchmittPernau, Hans-FridtjofHans-FridtjofPernauWöllenstein, JürgenJürgenWöllenstein2022-03-052022-03-052018https://publica.fraunhofer.de/handle/publica/25496410.3390/proceedings2131036In times of steadily increasing air pollution especially in urban areas, the monitoring of nitrogen dioxide (NO2) has gained in importance and with it the search for compact, low-cost sensors. We present a novel approach to measure NO2 in sub-ppm concentrations with a photoacoustic sensor utilizing a T-shaped resonance cell. An inexpensive single LED with a peak wavelength of 410 nm was used as radiation source and the acoustic detection was done with a commercial MEMS microphone. For optimal coupling of the divergent LED light into the cell, the T-shaped resonator was developed and fabricated with rapid prototyping methods. The resonator shows a acoustic Q-factor >10 while having nearly no zero gas signal.enresonant photoacoustic sensorLEDNO2 detection621journal article