caa a22 4500 445371374 CHVBK 20180317142947.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s00340-011-4518-z doi (NATIONALLICENCE)springer-10.1007/s00340-011-4518-z Frequency-stabilized cavity ring-down spectroscopy measurements of carbon dioxide isotopic ratios [Elektronische Daten] [D. Long, M. Okumura, C. Miller, J. Hodges] Carbon dioxide (CO2) isotopic ratios on samples of pure CO2 were measured in the 1.6 μm wavelength region using the frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) technique. We present CO2 absorption spectra with peak signal-to-noise ratios as high as 28,000:1. Measured single-spectrum signal-to-noise ratios were as high as 8900:1, 10,000:1, and 1700:1 for 13C/12C, 18O/16O, and 17O/16O, respectively. In addition, we demonstrate the importance of utilizing the Galatry line profile in the spectrum analysis. The use of the Voigt line profile, which neglects the observed collisional narrowing, leads to large systematic errors which are transition-dependent and vary with temperature and pressure. While the relatively low intensities of CO2 transitions near λ=1.6μm make this spectral region non-optimal, the sensitivity and stability of FS-CRDS enabled measurement precision of pure CO2 samples which are comparable to those of other optical techniques which operate at far more propitious wavelengths. These results indicate that a FS-CRDS spectrometer designed to probe CO2 bands near wavelengths of 2.0 μm or 4.3 μm could achieve significantly improved precision over the present instrument and likely be competitive with mass spectrometric methods. Springer-Verlag (outside the USA), 2011 Long D. Division of Chemistry and Chemical Engineering, California Institute of Technology, 91125, Pasadena, CA, USA aut Okumura M. Division of Chemistry and Chemical Engineering, California Institute of Technology, 91125, Pasadena, CA, USA aut Miller C. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, 91109, Pasadena, CA, USA aut Hodges J. Chemical and Biochemical Reference Data Division, National Institute of Standards and Technology, 100 Bureau Drive, 20899, Gaithersburg, MD, USA aut Applied Physics B Springer-Verlag 105/2(2011-11-01), 471-477 0946-2171 105:2<471 2011 105 340 https://doi.org/10.1007/s00340-011-4518-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00340-011-4518-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Long D. Division of Chemistry and Chemical Engineering, California Institute of Technology, 91125, Pasadena, CA, USA aut NATIONALLICENCE 700 1- Okumura M. Division of Chemistry and Chemical Engineering, California Institute of Technology, 91125, Pasadena, CA, USA aut NATIONALLICENCE 700 1- Miller C. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, 91109, Pasadena, CA, USA aut NATIONALLICENCE 700 1- Hodges J. Chemical and Biochemical Reference Data Division, National Institute of Standards and Technology, 100 Bureau Drive, 20899, Gaithersburg, MD, USA aut NATIONALLICENCE 773 0- Applied Physics B Springer-Verlag 105/2(2011-11-01), 471-477 0946-2171 105:2<471 2011 105 340 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer