Water Vapor Continuum Absorption in the 800 cm-1 to 1250 cm-1 Spectral Region at Temperatures From 311 to 363 K

Published

March 11, 2008

Author(s)

Yuri I. Baranov, Walter J. Lafferty, Q Ma, R H. Tipping

Abstract

About 200 pure water-vapor spectra covering the region from 800 cm-1 to 3500 cm-1 were recorded with resolution of 0.1 cm-1 at temperatures 311, 318, 325, 339, 352, and 363 K using a 2 m base White cell coupled to the BOMEM DA8.002 FTIR spectrometer. The water-vapor pressure varied from 28 to 151 mbar (21 to 113 torr). Under these conditions, the continuum absorbance is quite measurable with the available path lengths up to 116 m. A program was developed for spectral processing that calculates, fits, and removes ro-vibrational structure from the spectrum. The spectra obtained were used to retrieve averaged and smoothed binary absorption coefficients over the region from 800 cm-1 to 1250 cm-1. Our continuum data extrapolated to room temperature are in reasonable agreement with the CKD continuum model. But at higher temperatures the CKD model provides very low values, which are up to 50% less than those experimentally measured.

Citation

Journal of Quantitative Spectroscopy and Radiative Transfer

Volume

109

Issue

12-13

Pub Type

Journals

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Keywords

calibration, hyperspectral, medical imaging, stray light

Citation

Baranov, Y. , Lafferty, W. , Ma, Q. and Tipping, R. (2008), Water Vapor Continuum Absorption in the 800 cm-1 to 1250 cm-1 Spectral Region at Temperatures From 311 to 363 K, Journal of Quantitative Spectroscopy and Radiative Transfer, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=841141 (Accessed November 8, 2024)