Smoke Gas Analysis by FTIR Method. Preliminary Investigation

Abstract

The FTIR spectrometer equipped with a long path gas cell was used in on-line gas analysis in connection with the Cone Calorimeter. It provided a sensitive and effective gas analyzer for the seven gases (CO, CO 2 , HCN, HC1, SO 2 , NO 2 and acrolein) measured. Test materials (PUR, PVC and wool carpet) produced at 50 kW/m 2 irradiance measurable concentrations of all the other gases except NO 2 and acrolein in spite of effective dilution of smoke gases by high air flow in the Cone Calorimeter. Concentrations of the gases evolved in the Cone Calorimeter could be measured frequently enough even from materials, which have short burning times. After careful calibration the precision of FTIR analysis can be the same as in commercial on-line gas analyzers. Actual precision of on-line specific gas analyzers may be even worse than that of FTIR because of overlapping impurities. The heatable sample line and gas cell ensures that components of the fire gas mixture do not condense on the walls on the way to the instrument. Because FTIR technique has capacity for on-line analysis and simultaneous measurement of several gases, it is a suitable analysis method to be used in connection with the Cone Calorimeter and with other fire tests. The sensitivity of FTIR method is adequate for toxicity evaluations. The analysis results can be used as data in mathematical models to predict toxic eflects in fires.

Quantitative Models for Prediction of Toxic Component Concentrations in Smoke Gases from FTIR Spectra

“…INLR is attractive in that all essential features of PLS are preserved, i.e. (1) it can handle many noisy and collinear variables, (2) it is stable and gives reliable results and (3) all PLS plots and diagnostics still apply.…”

High Temperature Oxygen Index Instrument with Quantitative FT-IR Gas Analysis

“…Mathematical Fourier transformation converts the interferogram (which is a function of position) to a spectrum (which is a function of wavelength) representing all the characteristic vibrational frequencies of the molecules in the infrared gas cell. The FIR method was previously utilized for smoke gas analysis in connection with a cone calorimeter [6].…”

The use of partial least squares (PLS) in quantitative FTIR: Determination of gas concentrations in smoke gases of burning textiles

“…5 4 0 4 . 5 6"" 0 .I5 " ' * 1 .I0 " " 1 .I5 " " 2 .b " " 2 .I5 The spectra indicated by the numbers 1,30,35 and 9 in the scores plot form the edge points of a parallellogram. They correspond to concentrations (CO,, H,O) of respectively (1005 ppm, 368 ppm), (15 100 ppm, 803 ppm), (15 100 ppm, 13 282 ppm) and (1005 ppm, 14773 ppm).…”