US EPA

1671086 

Journal Article 

Fire smoke gases analysis by FT-IR spectrometer 

Lian, CZ; Lu, Z; Liu, QH; Li, DK; Xu, XC 

2003 

430-432 

WOS:000189485100103 

Fourier transform infrared (FTIR) spectroscopy can be used for real-time gas analysis for multiple-component gas mixture, as well as to quantify the concentrations of a large number of gases simultaneously such as H2O, CO, CO2, NH3, HCl, HCN, HF, NO, NO2, SO2, HCHO (formaldehyde) and CH2CHCHO (acrolein). Nevertheless, the fire smoke gases usually may contain a lot of soot and numerous errors & analysis problems may be generated if the gas sample goes directly to the FTIR gas cell, thus a FT-IR gas sampling system is needed. It's sometimes difficult to identify the complex components of the fire gas and to perform quantitative analysis, since the spectra of two or more components are overlapped and interfered. Therefore, simple method based on Beer's law and spectral subtraction seems impossible to quantify the overlapping spectra. To overcome this problem, Modem FTIR systems use computerized programs and some mathematical techniques, like class least squares (CLS), partial least squares (PLS), principal component regression (PCR), cross-correction and factor analysis. In this paper an overview of methods for the analysis of complex mixture fire gases and some FTIR sampling matters need attention will be given and FTIR measurement procedures will be detailed. Finally the advantages and disadvantages of each method will be discussed and evaluated. 

FT-IR; sampling system; gas analysis; quantitative analysis method; fire