Gao Mg

Research of spectrum preprocessing based on wavelet transform and principal component analysis

The accuracy of spectrum preprocessing, as the precondition of precise qualitative and quantitative spectrum analysis, performs importantly. This paper presents a new approach of combining wavelet transform (WT) with principal component analysis (PCA) in the preprocessing of spectrum analysis. The multi-scale characteristic of WT in time and frequency domain is utilized to extract useful signals and eliminate the noise and the baseline excursion from the spectrum; meanwhile, PCA method which can lower data dimension effectively and rapidly is adopted to deal with the overlapped, crossed and redundant information that exists in the spectrum. Application of the new approach in the analysis of samples is mainly discussed in this paper. The result of experiment shows that this method is suitable and advanced.

Industrial Air Pollution Monitoring by Active and Passive Fourier Transform Infrared Spectroscopy

Fourier Transform infrared spectroscopy has been widely used to measure chemical species of industrial emission. It becomes one of the most powerful tools for monitoring of industrial air pollution. Both active and passive systems, such as open path FTIR, closed White cell based FTIR and Solar Occultation Flux FTIR techniques were presented. The quantitative algorithm to retrieve the gas concentration from the measured spectrum by using the nonlinear least squares method were presented. The outcome indicates that, FTIR system allows mobile, real-time and fast measurements of industrial pollution.

The Study of VOCs Emission Monitoring Technology based on SOF-FTIR

SOF-FTIR,Solar Occulation Flux is a newly developed technology that used to monitor the VOCs on close path.Experiments were held in Shijiazhuang, with the NLS method,the concentration and flux of ethylbenzene and m-Xylene can be obtained.