The use of infrared thermography to study the optical characteristics of flames from burning vegetation

•In IR thermographic analysis of flames in the burning of vegetative combustible materials and/or ethyl alcohol, it is recommended to use the 2.5–3.3 μm spectral band.•High-temperature objects should be thermographically monitored via flames in the 4.0–5.0 μm spectral band.•Temperature spatial/temporal variations in the flame of vegetative combustible materials occur at 2–7 Hz, while burning ethyl alcohol reveals significant emission at about 16 Hz.

Some optical phenomena observed in the flames from the burning of flammable vegetation materials and ethyl alcohol are analyzed. Recommendations on the optimal spectral bands for temperature measurements of hot objects obscured by flames are given. Frequency spectra of temperature pulsations in flames are obtained, thus revealing a spatial structure in the flow of combustion products, as well as the degree of turbulence in a high temperature fluid medium.