% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@INPROCEEDINGS{Wegener:890283,
      author       = {Wegener, Robert},
      title        = {{I}ntercomparison of nitrogen monoxide and nitrogen dioxide
                      measurements in the atmosphere simulation chamber {SAPHIR}
                      during the {M}et{NO}2 campaign},
      reportid     = {FZJ-2021-00864},
      year         = {2020},
      abstract     = {<p>Nitrogen dioxide (NO<sub>2</sub>) and nitrogen monoxide
                      (NO) govern the photochemical processes in the troposphere.
                      Although nitrogen oxides have been measured for decades,
                      their quantification remains challenging. The MetNO2
                      (Metrology for Nitrogen Dioxide) project of the European
                      Metrology Programme for Innovation and Research (EMPIR) aims
                      to improve the accuracy of NO<sub>2</sub>
                      measurements.</p><p>In total 15 instruments were
                      intercompared at the World Calibration Centre for nitrogen
                      oxides (WCC-NOx) in $J\&#252;lich$ in autumn 2019 within the
                      project. In addition to chemiluminescence detectors (CLD),
                      the instruments encompassed Quantum Cascade Laser Absorption
                      Spectrometers (QCLAS), Iterative CAvity-enhanced
                      Differential optical absorption spectrometers (ICAD) and
                      Cavity Attenuated Phase Shift (CAPS)
                      spectrometers.</p><p>During the campaign, air from a gas
                      phase titration unit, air from the environmental chamber
                      SAPHIR or outside air was provided to the instruments via a
                      common inlet line. The participants calibrated their
                      instruments prior and after the campaign with their own
                      calibration procedures. During the campaign, the common
                      inlet line was used for daily calibration to compare
                      standards, calibration techniques and sensitivity drifts of
                      the instruments. NO<sub>2</sub> for calibration was provided
                      either by gas phase titration from NO, from permeation tubes
                      or from gas mixtures produced within the MetNO2
                      project.</p><p>It was observed that measurements by
                      chemiluminescence or CAPS instruments are prone to
                      interferences from humidity and ozone. However, in most
                      cases data can be corrected. Alkyl nitrates and reactive
                      alkenes were also observed to cause interferences in some
                      instruments, while isobutyl nitrite was found to be
                      photolyzed by photolytic converters.</p><p>Finally,
                      measurements in ambient air were compared. The nitrogen
                      oxide observations were accompanied with measurements of
                      hydroxyl radical (OH) reactivity and reactive nitrogen
                      species as nitrous acid (HONO), dinitrogen pentoxide
                      (N<sub>2</sub>O<sub>5</sub>), and chloryl nitrate
                      (ClNO<sub>2</sub>). Detailed results of the intercomparison
                      will be presented.</p>},
      month         = {May},
      date          = {2020-05-04},
      organization  = {EGU 2020, Online (Vienna), 4 May 2020
                       - 8 May 2020},
      subtyp        = {Other},
      cin          = {IEK-8},
      cid          = {I:(DE-Juel1)IEK-8-20101013},
      pnm          = {243 - Tropospheric trace substances and their
                      transformation processes (POF3-243)},
      pid          = {G:(DE-HGF)POF3-243},
      typ          = {PUB:(DE-HGF)6},
      doi          = {10.5194/egusphere-egu2020-6069},
      url          = {https://juser.fz-juelich.de/record/890283},
}