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| Titel |
Field inter-comparison of eleven atmospheric ammonia measurement techniques |
| VerfasserIn |
K. Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. Mcgillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz |
| 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 ; 3, no. 1 ; Nr. 3, no. 1 (2010-01-27), S.91-112 |
| Datensatznummer |
250000816
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| Publikation (Nr.) |
 copernicus.org/amt-3-91-2010.pdf |
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| Zusammenfassung |
| Eleven instruments for the measurement of ambient concentrations of
atmospheric ammonia gas (NH3), based on eight different measurement
methods were inter-compared above an intensively managed agricultural field
in late summer 2008 in Southern Scotland. To test the instruments over a
wide range of concentrations, the field was fertilised with urea midway
through the experiment, leading to an increase in the average concentration
from 10 to 100 ppbv. The instruments deployed included three wet-chemistry
systems, one with offline analysis (annular rotating batch denuder, RBD) and
two with online-analysis (Annular Denuder sampling with online Analysis,
AMANDA; AiRRmonia), two Quantum Cascade Laser Absorption Spectrometers (a
large-cell dual system; DUAL-QCLAS, and a compact system; c-QCLAS), two
photo-acoustic spectrometers (WaSul-Flux; Nitrolux-100), a Cavity Ring Down
Spectrosmeter (CRDS), a Chemical Ionisation Mass Spectrometer (CIMS), an ion
mobility spectrometer (IMS) and an Open-Path Fourier Transform
Infra-Red (OP-FTIR) Spectrometer. The instruments were compared with each
other and with the average concentration of all instruments. An overall good
agreement of hourly average concentrations between the instruments
(R2>0.84), was observed for NH3 concentrations at the field of up to
120 ppbv with the slopes against the average ranging from 0.67 (DUAL-QCLAS)
to 1.13 (AiRRmonia) with intercepts of −0.74 ppbv (RBD) to +2.69 ppbv
(CIMS). More variability was found for performance for lower concentrations
(<10 ppbv). Here the main factors affecting measurement precision are
(a) the inlet design, (b) the state of inlet filters (where applicable), and
(c) the quality of gas-phase standards (where applicable). By reference to the
fast (1 Hz) instruments deployed during the study, it was possible to
characterize the response times of the slower instruments. |
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