Spectroscopy differential optical absorption

Edner, Hans, Anders Sunesson, Sune Svanberg, Leif Llneus, and. Svante Wallin. Differential Optical Absorption Spectroscopy System Used for Atmospheric Mercury Monitoring. Applied Optics 25 (1986), pp. 403-409. 

Winer, A. M and H. W. Biermann, Long Pathlength Differential Optical Absorption Spectroscopy (DOAS) Measurements of Gaseous HONO, N02, and HCHO in the California South Coast Air Basin, Res. Chem. Intermed., 20, 423-445 (1994). 

Brauers, T., M. Hausmann, U. Brandenburger, and H.-P. Dorn, Improvement of Differential Optical Absorption Spectroscopy with a Multichannel Scanning Technique, Appl. Opt., 34, 4472-4479 (1995). 

Plane, J. M. C., and N. Smith, Atmospheric Monitoring by Differential Optical Absorption Spectroscopy, in Spectroscopy in Envi-... 

Platt, U Differential Optical Absorption Spectroscopy (DOAS), in Air Monitoring by Spectroscopic Techniques (M. W. Sigrist, Ed.), Chemical Analysis Series, Vol. 127, pp. 27-84, Wiley, New York, 1994. 

Stutz, J., and U. Platt, Numerical Analysis and Estimation of the Statistical Error of Differential Optical Absorption Spectroscopy Measurements with Least-Squares Methods, Appl. Opt., 35, 6041-6053 (1996),... 

GASCOD-A uses the differential optical absorption spectroscopy (DOAS) technique. It operates in the UV-visible spectral region and enables the detection of the trace gases listed in Table 4. The deliveries of GASCOD-A are total amounts of the trace constituents at zenith and nadir as well as vertical profiles. 

GOME is a nadir sounding spectrometer which observes the up-welling radiance from the top of the atmosphere and the extra-terrestrial solar irradiance between 240 and 790 nm. The resolution of the measurements is chosen to be suitable for the application of the differential optical absorption spectroscopy (DOAS) technique, which was developed for long-path measurements and zenith sky observations (e.g. Platt and Pemer, 1980 Mounter a/., 1987 Eisinger etal., 1997). 

Platt, U. and D. Pemer (1980) Direct measurements of atmospheric HCHO, HONO, O3, NO2, and SO], by differential optical absorption spectroscopy in the near UV. Journal of Geophysical Research 85 7453-7465. 

Note NA = not applicable FID = flame ionization detector DOAS = differential optical absorption spectroscopy. 

Honninger G. (2002) Halogen oxide smdies in the boundary layer by multi axis differential optical absorption spectroscopy and active longpath-DOAS. PhD Thesis, Universi-tat Heidelberg, Germany, http //www.ub.uni-heidelberg.de/ archiv/1940... 

Remote Sensing of Glyoxal by Differential Optical Absorption Spectroscopy... 

Measurements of glyoxal (CHOCHO) by Differential Optical Absorption Spectroscopy (DOAS) are feasible on a routine basis in the Mexico City Metropolitan Area (MCMA) and other... 

Platt, U. (1994), Differential Optical Absorption Spectroscopy, in Monitoring by Spectroscopic Techniques, edited by Sigrist, M.W., chapter 2, 27-84, Wiley Sons, New York. 

Other common techniques for the determination of NO2 are laser absorption spectroscopy, fluorescence or photo-acoustic spectrometry, or also differential optical absorption spectroscopy. Instrumentation of those methods is mostly complicated, and expensive to operate and maintain. 

Various methods have been developed for remote gas sensing. These include differential optical-absorption spectroscopy (DOAS), differential absorption lidar (DIAL), and a number of methods that use spectroscopic methods with an atmospheric path in place of a laboratory long-path cell, for example tunable diode laser absorption spectroscopy (TDLAS) and Fourier transform infrared (FTIR) spectroscopy. 

Four different methods used for integrated-path remote gas sensing are discussed here. One of these (tunable diode laser absorption spectroscopy, TOLAS) uses a narrow linewidth source of radiation (usually a laser diode) and the other three methods use broadband sources of radiation. These three analyze the spectrum of the radiation after it has traversed the atmospheric path in different ways both differential optical absorption spectroscopy (DOAS) and Fourier transform infrared (FTIR) spectroscopy analyze the entire spectrum over the spectral region of interest, whilst absorption correlation methods record the spectrum after it has been filtered optically with either an optical filter or a sample of the target gas itself. These four methods use an active source of radiation. It is also possible to carry out integrated-path remote gas sensing using a passive source. 

H. Edner, A. Sunesson, S. Svanberg, L. Uneus, S. Wallin Differential optical absorption spectroscopy system used for atmospheric mercury monitoring. Appl. Opt. 25, 403 (1986)... 

H. Edner, P. Ragnarson, S. Spannare, S. Svanberg A differential optical absorption spectroscopy (DOAS) system for urban atmospheric pollution monitoring. Appl. Opt. 32, 327 (1993) and Lund Reports on Atomic Physics LRAP-133 (Lund Institute of Technology, Lund 1992)... 

P. Weibring, H. Edner, S. Svanberg, G. Cecchi, L. Pantani, R. Ferrara, T. Caltabiano Monitoring of volcanic sulphur dioxide emissions using differential absorption lidar (DIAL), differential optical absorption spectroscopy (DOAS), and correlation spectroscopy (COSPEC). Appl, Phys. B 67, 419 (1998)... 

H. Edner, P. Ragnarson, S. Svanberg, E. Wallinder, R. Ferrara, R. Cioni, B. Raco, G. Taddeucci Total fluxes of sulphur dioxide from the Italian volcanoes Etna, Stromboli and Vuicano measured by differential absorption hdar and passive differential optical absorption spectroscopy. J. Geophys. Res. 99, 18 827 (1994)... 

The typical atmospheric concentrations of OH and HO2 radicals in the daytime are 10 and 10 molecules cm ( 0.1 pptv and a few pptv), respectively. The detection techniques whose accuracy is thought to be satisfactory for their measurements are laser-induced fluorescence (LIF) at low pressure which is called Fluorescence Assay by Gas Expansion (FACE), and chemical ionization mass spectrometry (CIMS), and they have recently been used widely. In either of the methods, directly measured is OH, and HO2 is measured by converting to OH utilizing the reaction of HO2 -I- NO —> OH -I- NO2 (reaction (7.10)) adding NO to the atmospheric samples just before the introduction to the detector. Other than these methods, differential optical absorption spectroscopy (DOAS) is also used for the measurements of OH in fields and smog chambers. 

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