This work is aimed at helping the Building and Fire Research of NIST develop methods to better quantify the behavior of fire so its impact on people, property, and the environment can be reduced. Thermal radiation from the combustion zone in flames to the fuel bed is known be a significant factor in determining the rate at which a fuel volatilizes. Because thermal radiation from the flame must pass through a relatively cool, fuel-rich layer near the fuel bed, the absorption spectra of this layer must be accurately known if modeling of flames is to be performed with confidence. Unfortunately, measurements at such high temperatures (up to 1100 K) are difficult to perform, and data is available for only a few species. The primary objectives are to make absorption measurements in an existing rig at intermediate temperatures (up to 700 K), modify the rig so measurements can be made at high temperatures, validate these high temperature measurements using additional measurements and modeling of simple fires, then incorporate the new data into a database.

The effort consists of several tasks to build and validate the database for spectral absorption coefficients. An existing FTIR (Fourier Transform Infrared Spectroscopy) rig has been modified so that measurements can be obtained at temperatures up to 1100 K by providing cooling of the ZnSe windows. Measurements of propane, heptane, methanol, and toluene have been obtained to date, and this information is being incorporated into the RADCAL database.

This work is being performed in conjunction with Dr. Greg Jackson, and is supported by the Fire Research Division at NIST.