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Published on: March 22, 2019
[Study on the arithmetic of absorbance inversion based on tunable diode-laser absorption spectroscopy].
Zhen-yu Xu1, Wen-qing Liu, Rui-feng Kan
1Key Lab of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China. zyxu@aiofm.ac.cn
Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu
|October 14, 2010
Summary
This study presents a new method for processing tunable diode-laser absorption spectroscopy data. The technique accurately determines gas concentrations by fitting absorbance curves and integrated absorbance, validated with water vapor experiments.
Area of Science:
- Spectroscopy
- Analytical Chemistry
- Laser Technology
Context:
- Tunable diode-laser absorption spectroscopy (TDLAS) is crucial for environmental monitoring and industrial process detection.
- High spectral resolution, sensitivity, fast response, and nonintrusive nature make TDLAS versatile.
- Accurate gas concentration inversion and line strength calibration rely on absorbance curve and integrated absorbance data.
Purpose:
- To develop and validate an approach for processing direct absorption spectra obtained from TDLAS.
- To accurately derive absorbance curves and integrated absorbance from raw spectral data.
- To enable precise gas concentration measurements and spectroscopic parameter calibration.
Summary:
- A novel method processes laser direct absorption spectra by applying low-order polynomial baseline fitting to sub-regions of the transmitted signal.
- This fitting eliminates diode-laser output fluctuations, yielding accurate absorbance curves.
- Integrated absorbance is subsequently inverted using Levenberg-Marquardt non-linear least-squares fitting, validated with water vapor absorption lines.
Impact:
- Provides a robust method for analyzing TDLAS data, enhancing accuracy in gas sensing applications.
- Improves the reliability of gas concentration inversion and line strength calibration in various scientific and industrial fields.
- Demonstrates the effectiveness of the developed spectral processing technique through experimental validation.
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