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Title: Scattered light and accuracy of the cross-section measurements of weak absorptions: Gas and liquid phase UV absorption cross sections of CH{sub 3}CFCl{sub 2}

Abstract

Ultraviolet absorption cross sections of CH{sub 3}CFCl{sub 2} (HCFC-141b) were determined in the gas phase (190-260 nm) and liquid phase (230-260 mm) at 298 K. The liquid phase absorption cross sections were then converted into accurate gas phase values using a previously described procedure. It has been demonstrated that scattered light from the shorter-wavelength region (as little as several parts per thousand) can seriously compromise the absorption cross-section measurement, particularly at longer wavelengths where cross sections are low, and can be a source of discrepancies in the cross sections of weakly absorbing halocarbons reported in the literature. A modeling procedure was developed to assess the effect of scattered light on the measured absorption cross section in these experiments, thereby permitting appropriate corrections to be made on the experimental values. Modeled and experimental results were found to be in good agreement. Experimental results from this study were compared with other available determinations and provide accurate input for calculating the atmospheric lifetime of HCFC-141b. 8 refs., 3 figs., 1 tab.

Authors:
; ;  [1]
  1. National Institute of Standards and Technology, Gaithersburg, MD (United States)
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
160383
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research
Additional Journal Information:
Journal Volume: 98; Journal Issue: D11; Other Information: PBD: 20 Nov 1993
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; ORGANIC HALOGEN COMPOUNDS; ABSORPTION; CROSS SECTIONS; ULTRAVIOLET RADIATION; TEMPERATURE RANGE 0273-0400 K

Citation Formats

Fahr, A, Braun, W, and Kurylo, M J. Scattered light and accuracy of the cross-section measurements of weak absorptions: Gas and liquid phase UV absorption cross sections of CH{sub 3}CFCl{sub 2}. United States: N. p., 1993. Web. doi:10.1029/93JD01086.
Fahr, A, Braun, W, & Kurylo, M J. Scattered light and accuracy of the cross-section measurements of weak absorptions: Gas and liquid phase UV absorption cross sections of CH{sub 3}CFCl{sub 2}. United States. https://doi.org/10.1029/93JD01086
Fahr, A, Braun, W, and Kurylo, M J. Sat . "Scattered light and accuracy of the cross-section measurements of weak absorptions: Gas and liquid phase UV absorption cross sections of CH{sub 3}CFCl{sub 2}". United States. https://doi.org/10.1029/93JD01086.
@article{osti_160383,
title = {Scattered light and accuracy of the cross-section measurements of weak absorptions: Gas and liquid phase UV absorption cross sections of CH{sub 3}CFCl{sub 2}},
author = {Fahr, A and Braun, W and Kurylo, M J},
abstractNote = {Ultraviolet absorption cross sections of CH{sub 3}CFCl{sub 2} (HCFC-141b) were determined in the gas phase (190-260 nm) and liquid phase (230-260 mm) at 298 K. The liquid phase absorption cross sections were then converted into accurate gas phase values using a previously described procedure. It has been demonstrated that scattered light from the shorter-wavelength region (as little as several parts per thousand) can seriously compromise the absorption cross-section measurement, particularly at longer wavelengths where cross sections are low, and can be a source of discrepancies in the cross sections of weakly absorbing halocarbons reported in the literature. A modeling procedure was developed to assess the effect of scattered light on the measured absorption cross section in these experiments, thereby permitting appropriate corrections to be made on the experimental values. Modeled and experimental results were found to be in good agreement. Experimental results from this study were compared with other available determinations and provide accurate input for calculating the atmospheric lifetime of HCFC-141b. 8 refs., 3 figs., 1 tab.},
doi = {10.1029/93JD01086},
url = {https://www.osti.gov/biblio/160383}, journal = {Journal of Geophysical Research},
number = D11,
volume = 98,
place = {United States},
year = {1993},
month = {11}
}