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Near-infrared transmission spectroscopy of aqueous solutions: Influence of optical pathlength on signal-to-noise ratio

Snoer Jensen, Peter LU and Bak, J (2002) In Applied Spectroscopy 56(12). p.1600-1606
Abstract
The optimal choice of optical pathlength, source intensity, and detector for near-infrared transmission measurements of trace components in aqueous solutions depends on the strong absorption of water. In this study we examine under which experimental circumstances one may increase the pathlength to obtain a measurement with higher signal-to-noise ratio. The noise level of measurements at eight different pathlengths from 0.2 to 2.0 mm of pure water and of 1 g/dL aqueous glucose signals were measured using a Fourier transform near-infrared spectrometer and a variable pathlength transmission cell. The measurements demonstrate that the noise level is determined by the water transmittance. The noise levels in the spectral region from 5000 to... (More)
The optimal choice of optical pathlength, source intensity, and detector for near-infrared transmission measurements of trace components in aqueous solutions depends on the strong absorption of water. In this study we examine under which experimental circumstances one may increase the pathlength to obtain a measurement with higher signal-to-noise ratio. The noise level of measurements at eight different pathlengths from 0.2 to 2.0 mm of pure water and of 1 g/dL aqueous glucose signals were measured using a Fourier transform near-infrared spectrometer and a variable pathlength transmission cell. The measurements demonstrate that the noise level is determined by the water transmittance. The noise levels in the spectral region from 5000 to 4000 cm(-1) show that the optimal pathlength (0.4 mm) is the same for pure water and 1 g/dL aqueous glucose solutions. When detector saturation occurs it is favorable to increase the pathlength instead of attenuating the light source. The obtained results are explained by an analytical model. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
transmission, near-infrared spectroscopy, instrument configuration, optimal pathlength, FT-NIR, detector saturation, scattering
in
Applied Spectroscopy
volume
56
issue
12
pages
1600 - 1606
publisher
Society for Applied Spectroscopy
external identifiers
  • wos:000180011700015
  • scopus:0036971625
ISSN
1943-3530
DOI
10.1366/000370202321115878
language
English
LU publication?
yes
id
17173c9c-c66a-4e19-b644-e5cbf9234970 (old id 321144)
alternative location
http://www.opticsinfobase.org/abstract.cfm?URI=as-56-12-1600
date added to LUP
2007-11-05 10:53:00
date last changed
2017-08-13 03:47:51
@article{17173c9c-c66a-4e19-b644-e5cbf9234970,
  abstract     = {The optimal choice of optical pathlength, source intensity, and detector for near-infrared transmission measurements of trace components in aqueous solutions depends on the strong absorption of water. In this study we examine under which experimental circumstances one may increase the pathlength to obtain a measurement with higher signal-to-noise ratio. The noise level of measurements at eight different pathlengths from 0.2 to 2.0 mm of pure water and of 1 g/dL aqueous glucose signals were measured using a Fourier transform near-infrared spectrometer and a variable pathlength transmission cell. The measurements demonstrate that the noise level is determined by the water transmittance. The noise levels in the spectral region from 5000 to 4000 cm(-1) show that the optimal pathlength (0.4 mm) is the same for pure water and 1 g/dL aqueous glucose solutions. When detector saturation occurs it is favorable to increase the pathlength instead of attenuating the light source. The obtained results are explained by an analytical model.},
  author       = {Snoer Jensen, Peter and Bak, J},
  issn         = {1943-3530},
  keyword      = {transmission,near-infrared spectroscopy,instrument configuration,optimal pathlength,FT-NIR,detector saturation,scattering},
  language     = {eng},
  number       = {12},
  pages        = {1600--1606},
  publisher    = {Society for Applied Spectroscopy},
  series       = {Applied Spectroscopy},
  title        = {Near-infrared transmission spectroscopy of aqueous solutions: Influence of optical pathlength on signal-to-noise ratio},
  url          = {http://dx.doi.org/10.1366/000370202321115878},
  volume       = {56},
  year         = {2002},
}