TY - JOUR
T1 - Validation of the calibration of a laser-induced fluorescence instrument for the measurement of OH radicals in the atmosphere
AU - Bloss, W. J.
AU - Lee, J. D.
AU - Bloss, C.
AU - Heard, D. E.
AU - Pilling, M. J.
AU - Wirtz, K.
AU - Martin-Reviejo, M.
AU - Siese, M.
PY - 2004
Y1 - 2004
N2 - An assessment of the accuracy of OH concentrations measured in a smog chamber by a calibrated laser-induced fluorescence (LIF) instrument has been made, in the course of 9 experiments performed to study the photo-oxidation of benzene, toluene, 1,3,5-trimethylbenzene, paraxylene, ortho-cresol and ethene at the European Photoreactor facility (EUPHORE). The LIF system was calibrated via the water photolysis / ozone actinometry approach. OH concentrations were inferred from the instantaneous rate of removal of each hydrocarbon species (measured by FTIR or HPLC) via the appropriate rate coefficient for their reaction with OH, and compared with those obtained from the LIF system. Good agreement between the two approaches was found for all species with the exception of 1,3,5-trimethylbenzene, for which OH concentrations inferred from hydrocarbon removal were a factor of 3 lower than those measured by the LIF system. From the remaining 8 experiments, an overall value of 1.15±0.13 (±1σ) was obtained for [OH]LIF / [OH]HydrocarbonDecay, compared with the estimated uncertainty in the accuracy of the water photolysis / ozone actinometry OH calibration technique of 26% (1 σ).
AB - An assessment of the accuracy of OH concentrations measured in a smog chamber by a calibrated laser-induced fluorescence (LIF) instrument has been made, in the course of 9 experiments performed to study the photo-oxidation of benzene, toluene, 1,3,5-trimethylbenzene, paraxylene, ortho-cresol and ethene at the European Photoreactor facility (EUPHORE). The LIF system was calibrated via the water photolysis / ozone actinometry approach. OH concentrations were inferred from the instantaneous rate of removal of each hydrocarbon species (measured by FTIR or HPLC) via the appropriate rate coefficient for their reaction with OH, and compared with those obtained from the LIF system. Good agreement between the two approaches was found for all species with the exception of 1,3,5-trimethylbenzene, for which OH concentrations inferred from hydrocarbon removal were a factor of 3 lower than those measured by the LIF system. From the remaining 8 experiments, an overall value of 1.15±0.13 (±1σ) was obtained for [OH]LIF / [OH]HydrocarbonDecay, compared with the estimated uncertainty in the accuracy of the water photolysis / ozone actinometry OH calibration technique of 26% (1 σ).
UR - http://www.scopus.com/inward/record.url?scp=3242661936&partnerID=8YFLogxK
U2 - 10.5194/acp-4-571-2004
DO - 10.5194/acp-4-571-2004
M3 - Article
AN - SCOPUS:3242661936
SN - 1680-7316
VL - 4
SP - 571
EP - 583
JO - Atmospheric Chemistry and Physics
JF - Atmospheric Chemistry and Physics
IS - 2
ER -