Infrared Thermographic Diagnostics of Wood Fire Resistance under Combined Thermal Effect Conditions from a Ground Fire Front and Firebrands

Experiments were conducted on certain types of combustible building materials and wood-based structures to determine the interaction between firebrands and forest fuel (FF). Using non-contact IR diagnostic methods in narrow spectral ranges of infrared wavelengths, the heat flux values generated by firebrands and the temperature field of the most heat-stressed sections of the structures under study were determined. Using a JADE J530SB thermal imager with an optical filter of 2,5—2,7 m, temperatures in the range 310—1500 K were measured in the infrared region. In order to interpret the recorded emission from the test sample, calibrations supplied by the narrowband optical filter manufacturer were used.