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| Titel |
EMRP JRP MetNH3: Towards a Consistent Metrological Infrastructure for Ammonia Measurements in Ambient Air |
| VerfasserIn |
Daiana Leuenberger, David Balslev-Harder, Christine F. Braban, Volker Ebert, Valerio Ferracci, Bjoern Gieseking, Tuomas Hieta, Nicholas A. Martin, Céline Pascale, Andrea Pogány, Carlo Tiebe, Marsailidh M. Twigg, Olavi Vaittinen, Janneke van Wijk, Klaus Wirtz, Bernhard Niederhauser |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250135366
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| Publikation (Nr.) |
 EGU/EGU2016-16221.pdf |
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| Zusammenfassung |
| Measuring ammonia in ambient air is a sensitive and priority issue due to its harmful effects
on human health and ecosystems. In addition to its acidifying effect on natural waters and
soils and to the additional nitrogen input to ecosystems, ammonia is an important precursor
for secondary aerosol formation in the atmosphere. The European Directive 2001/81/EC on
“National Emission Ceilings for Certain Atmospheric Pollutants (NEC)” regulates ammonia
emissions in the member states. However, there is a lack of regulation regarding certified
reference material (CRM), applicable analytical methods, measurement uncertainty, quality
assurance and quality control (QC/QA) procedures as well as in the infrastructure to attain
metrological traceability.
As shown in a key comparison in 2007, there are even discrepancies between
reference materials provided by European National Metrology Institutes (NMIs) at
amount fraction levels up to three orders of magnitude higher than ambient air
levels.
MetNH3 (Metrology for ammonia in ambient air), a three-year project that started in June
2014 in the framework of the European Metrology Research Programme (EMRP), aims to
reduce the gap between requirements set by the European emission regulations and
state-of-the-art of analytical methods and reference materials.
The overarching objective of the JRP is to achieve metrological traceability for
ammonia measurements in ambient air from primary certified reference material
CRM and instrumental standards to the field level. This requires the successful
completion of the three main goals, which have been assigned to three technical work
packages:
To develop improved reference gas mixtures by static and dynamic gravimetric
generation methods
Realisation and characterisation of traceable preparative calibration standards (in
pressurised cylinders as well as mobile generators) of ammonia amount fractions similar to
those in ambient air based on existing methods for other reactive analytes. The aimed
uncertainty is < 1 % for static mixtures at the 10 to 100 μmol/mol level, and < 3 % for
portable dynamic generators in the 0 to 500 nmol/mol amount fraction range. Special
emphasis is put on the minimisation of adsorption losses.
To develop and characterise laser based optical spectrometric standards
Evaluation and characterisation of the applicability of a newly developed open-path as
well as of existing extractive measurement techniques as optical transfer standards according
to metrological standards.
To establish the transfer from high-accuracy standards to field applicable
methods
Employment of characterised exposure chambers as well as field sites for validation and
comparison experiments to test and evaluate the performance of different instruments and
measurement methods at ammonia amount fractions of the ambient air.
The active exchange in workshops and inter-comparisons, publications in technical
journals as well as presentations at relevant conferences and standardisation bodies will
transfer the knowledge to stakeholders and end-users.
The work has been carried out in the framework of the EMRP. The EMRP is jointly
funded by the EMRP participating countries within EURAMET and the European Union. |
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