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| Titel |
Characterization and testing of a new environmental chamber |
| VerfasserIn |
A. Leskinen, P. Yli-Pirilä, K. Kuuspalo, O. Sippula, P. Jalava, M.-R. Hirvonen, J. Jokiniemi, A. Virtanen, M. Komppula, K. E. J. Lehtinen |
| 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 ; 8, no. 6 ; Nr. 8, no. 6 (2015-06-03), S.2267-2278 |
| Datensatznummer |
250116419
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| Publikation (Nr.) |
 copernicus.org/amt-8-2267-2015.pdf |
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| Zusammenfassung |
| A 29 m3 Teflon chamber, designed for studies on the aging of combustion
aerosols, at the University of Eastern Finland is described and
characterized. The chamber is part of a research facility, called Ilmari,
where small-scale combustion devices, a dynamometer for vehicle exhaust
studies, dilution systems, the chamber, and cell and animal exposure
devices are located side by side under the same roof. The small
surface-to-volume ratio of the chamber enables reasonably long experiment
times, with particle wall loss rate constants of 0.088, 0.080, 0.045, and
0.040 h−1 for polydisperse, 50, 100, and 200 nm monodisperse aerosols,
respectively. The NO2 photolysis rate can be adjusted from 0 to
0.62 min−1. The irradiance spectrum is centered at either 350 or
365 nm, and the maximum irradiance, produced by up to 160 blacklight lamps,
is 29.7 W m−2, which corresponds to the ultraviolet (UV) irradiance in Central
Finland at noon on a sunny day in the midsummer. The temperature inside the
chamber is uniform and can be kept at 25±1 °C. The chamber
is kept in an overpressure with a moving top frame, which reduces sample
dilution and entrance of contamination during an experiment. The
functionality of the chamber was tested with oxidation experiments of
toluene, resulting in secondary organic aerosol (SOA) yields of 12–42%,
depending on the initial conditions, such as NOx concentration and UV
irradiation. The highest gaseous oxidation product yields of 12.4–19.5%
and 5.8–19.5% were detected with ions corresponding to methyl glyoxal
(m/z 73.029) and 4-oxo-2-pentenal (m/z 99.044), respectively. Overall,
reasonable yields of SOA and gaseous reaction products, comparable to those
obtained in other laboratories, were obtained. |
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