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Titel |
Interferences of commercial NO2 instruments in the urban atmosphere and in a smog chamber |
VerfasserIn |
G. Villena, I. Bejan, R. Kurtenbach, P. Wiesen, J. Kleffmann |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1867-1381
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Measurement Techniques ; 5, no. 1 ; Nr. 5, no. 1 (2012-01-13), S.149-159 |
Datensatznummer |
250002313
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Publikation (Nr.) |
copernicus.org/amt-5-149-2012.pdf |
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Zusammenfassung |
Reliable measurements of atmospheric trace gases are necessary for both, a
better understanding of the chemical processes occurring in the atmosphere,
and for the validation of model predictions. Nitrogen dioxide (NO2) is
a toxic gas and is thus a regulated air pollutant. Besides, it is of major
importance for the oxidation capacity of the atmosphere and plays a pivotal
role in the formation of ozone and acid precipitation. Detection of NO2
is a difficult task since many of the different commercial techniques used
are affected by interferences. The chemiluminescence instruments that are
used for indirect NO2 detection in monitoring networks and smog
chambers use either molybdenum or photolytic converters and are affected by
either positive (NOy) or negative interferences (radical formation in
the photolytic converter). Erroneous conclusions on NO2 can be drawn if
these interferences are not taken into consideration. In the present study,
NO2 measurements in the urban atmosphere, in a road traffic tunnel and
in a smog-chamber using different commercial techniques, i.e. chemiluminescence instruments with molybdenum or photolytic converters, a
Luminol based instrument and a new NO2-LOPAP, were compared with
spectroscopic techniques, i.e. DOAS and FTIR. Interferences of the different
instruments observed during atmospheric measurements were partly
characterised in more detail in the smog chamber experiments. Whereas all
the commercial instruments showed strong interferences, excellent agreement
was obtained between a new NO2-LOPAP instrument and the FTIR technique
for the measurements performed in the smog chamber. |
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