- Yan Wang: Precision Instrument and Optoelectronie Engineering Department, Tianjin University, Tianjin 300072, China.
It is important to determine the optimal wavenumber ranges of spectra for quantitative analysis in gas detection. In traditional way, selection of optimal wavenumber ranges is based on the absorption characteristics of standard spectra, while this may introduce some deviation to the result due to its low capability of anti-interference. Two-dimensional correlation infrared spectroscopy technology was applied in gas detection in the present paper. The spectral structure and spectral information of SO2, NO and NO2 were analyzed in order to determine the optimal wavenumber range. The dynamic spectra of the detected gas were gained by the two-dimensional correlation analysis of a series of infrared absorption spectra according to changing concentrations. The most sensitive wavenumber ranges to gas concentration were determined by combining synchronous correlation spectra and asynchronous correlation spectra. These were taken as the optimal wavenumber ranges for quantitative gas analysis, which included a series of unattached wavenumber points and continous wavenumber ranges. Results showed that the selected wavenumber ranges were consistent with theoretic analyzed results. Two-dimensional correlation infrared spectroscopy can be a novel way to determine the optimal spectral range for gas analysis.