Detection of nitrogen dioxide by cavity attenuated phase shift spectroscopy.

@article{Kebabian2005DetectionON,
  title={Detection of nitrogen dioxide by cavity attenuated phase shift spectroscopy.},
  author={Paul L. Kebabian and Scott C Herndon and Andrew Freedman},
  journal={Analytical chemistry},
  year={2005},
  volume={77 2},
  pages={724-8}
}
We present initial results obtained from an optical absorption sensor for the monitoring of ambient atmospheric nitrogen dioxide concentrations (0-200 ppb). This sensor utilizes cavity attenuated phase shift spectroscopy, a technology related to cavity ringdown spectroscopy. A modulated broadband incoherent light source (a 430-nm LED) is coupled to an optically resonant cavity formed by two high-reflectivity mirrors. The presence of NO(2) in the cell causes a phase shift in the signal received… CONTINUE READING