TRIPLE Q: A three channel quantum cascade laser absorption spectrometer for fast multiple species concentration measurements

2011 ◽  
Vol 82 (9) ◽  
pp. 093102 ◽  
Author(s):  
M. Hübner ◽  
S. Welzel ◽  
D. Marinov ◽  
O. Guaitella ◽  
S. Glitsch ◽  
...  
2015 ◽  
Vol 8 (8) ◽  
pp. 8859-8902 ◽  
Author(s):  
J. R. Pitt ◽  
M. Le Breton ◽  
G. Allen ◽  
C. J. Percival ◽  
M. W. Gallagher ◽  
...  

Abstract. Spectroscopic measurements of atmospheric N2O and CH4 mole fractions were made on board the FAAM (Facility for Airborne Atmospheric Measurements) large Atmospheric Research Aircraft. We present details of the mid-IR Aerodyne Research Inc. Quantum Cascade Laser Absorption Spectrometer (QCLAS) employed, including its configuration for airborne sampling, and evaluate its performance over 17 flights conducted during summer 2014. Two different methods of correcting for the influence of water vapour on the spectroscopic retrievals are compared and evaluated. A new in-flight calibration procedure to account for the observed sensitivity of the instrument to ambient pressure changes is described, and its impact on instrument performance is assessed. Test flight data linking this sensitivity to changes in cabin pressure is presented. Total 1σ uncertainties of 1.81 ppb for CH4 and 0.35 ppb for N2O are derived. We report a mean difference in 1 Hz CH4 mole fraction of 2.05 ppb (1σ = 5.85 ppb) between in-flight measurements made using the QCLAS and simultaneous measurements using a previously characterised Los Gatos Research Fast Greenhouse Gas Analyser (FGGA). Finally, a potential case study for the estimation of a regional N2O flux using a mass balance technique is identified, and the method for calculating such an estimate is outlined.


2016 ◽  
Vol 9 (1) ◽  
pp. 63-77 ◽  
Author(s):  
J. R. Pitt ◽  
M. Le Breton ◽  
G. Allen ◽  
C. J. Percival ◽  
M. W. Gallagher ◽  
...  

Abstract. Spectroscopic measurements of atmospheric N2O and CH4 mole fractions were made on board the FAAM (Facility for Airborne Atmospheric Measurements) large atmospheric research aircraft. We present details of the mid-infrared quantum cascade laser absorption spectrometer (QCLAS, Aerodyne Research Inc., USA) employed, including its configuration for airborne sampling, and evaluate its performance over 17 flights conducted during summer 2014. Two different methods of correcting for the influence of water vapour on the spectroscopic retrievals are compared and evaluated. A new in-flight calibration procedure to account for the observed sensitivity of the instrument to ambient pressure changes is described, and its impact on instrument performance is assessed. Test flight data linking this sensitivity to changes in cabin pressure are presented. Total 1σ uncertainties of 2.47 ppb for CH4 and 0.54 ppb for N2O are derived. We report a mean difference in 1 Hz CH4 mole fraction of 2.05 ppb (1σ =  5.85 ppb) between in-flight measurements made using the QCLAS and simultaneous measurements using a previously characterised Fast Greenhouse Gas Analyser (FGGA, Los Gatos Research, USA). Finally, a potential case study for the estimation of a regional N2O flux using a mass balance technique is identified, and the method for calculating such an estimate is outlined.


2021 ◽  
Author(s):  
Akshay Nataraj ◽  
Michele Gianella ◽  
Ivan Prokhorov ◽  
Bela Tuzson ◽  
Mathieu Bertrand ◽  
...  

2014 ◽  
Vol 80 (6) ◽  
pp. 833-841 ◽  
Author(s):  
K. Ouaras ◽  
L. Colina Delacqua ◽  
G. Lombardi ◽  
J. Röpcke ◽  
M. Wartel ◽  
...  

The formation of carbon nanoparticles in low pressure magnetized H2/CH4and H2/C2H2plasmas is investigated using infrared quantum cascade laser absorption, mass spectrometry, and electrostatic probe measurements. Results showed that dust formation is correlated to the presence of a significant amount of large positively charged hydrocarbon ions. Large negative ions or neutral hydrocarbon were not observed. These results, along with a qualitative comparison of diffusion and reaction characteristic, suggest that a positive ion may contribute to the growth of nanoparticles in hydrocarbon magnetized plasmas.


Sign in / Sign up

Export Citation Format

Share Document