title: A compact broadband cavity enhanced absorption spectrometer for detection of atmospheric NO(2) using light emitting diodes.
abstract: A compact and low power detector has been developed for the in situ measurement of atmospheric NO(2) using broadband cavity enhanced absorption spectroscopy. Absorption by the O(2)-O(2) collisional pair was used to determine the cavity mirror reflectivity, thus enabling the retrieval of absolute absorber concentrations by differential spectral fitting techniques. Quantitative amounts of ambient NO(2) (between 3 and 32 parts per billion) were retrieved from spectra recorded in the presence of ambient aerosol with statistical uncertainties approaching 100 ppt for a 60 s averaging period. The instrument's response was compared to that of a commercial chemiluminescence detector and was found to agree to within 6%.
authors.affiliation: Department of Chemistry, University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge, UK CB2 1EW.
authors.forename: Justin M
authors.initials: JM
authors.lastname: Langridge
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Ball
authors.forename: Roderic L
authors.initials: RL
authors.lastname: Jones