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Updated: Jun 25, 2026
10:42
Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
Published on: March 22, 2019
[Using Fourier transform to calculate gas concentration in DOAS]
Qian-lin Liu1, Li-shi Wang, Xin-jian Huang
1College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510640, China.
Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu
|March 3, 2009
Summary
Differential Optical Absorption Spectrometry (DOAS) offers sensitive, real-time air pollution monitoring. A new Fourier transform method links gas spectrum frequency to concentration, simplifying analysis for pollutants like SO2 and NO.
Area of Science:
- Atmospheric chemistry and physics
- Spectroscopy and analytical chemistry
Context:
- Air pollution monitoring is crucial for environmental and public health.
- Differential Optical Absorption Spectrometry (DOAS) is an advanced technique for real-time atmospheric analysis.
- Gaseous pollutants like sulfur dioxide (SO2), nitrogen monoxide (NO), and nitrogen dioxide (NO2) significantly impact air quality.
Purpose:
- To develop a novel analysis method for DOAS by utilizing Fourier transform to analyze gas absorption spectra.
- To establish a linear relationship between characteristic frequency and gas concentration for accurate pollutant monitoring.
- To simplify spectral analysis and concentration calculation processes in DOAS.
Summary:
- This study proposes a new DOAS analysis method using Fourier transform to process periodic gas spectra (e.g., SO2, NO).
- The method establishes a linear relationship between characteristic frequency and gas concentration, enabling direct calculation.
- While effective for gases with evident periodicity, frequency separation is critical for improving accuracy in less periodic spectra.
Impact:
- Provides a simplified and potentially faster method for calculating pollutant concentrations using DOAS.
- Highlights the importance of frequency separation for enhancing the accuracy of this new DOAS analysis technique.
- Offers a foundation for further research and development in advanced atmospheric pollution monitoring.
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