Multi-wavelength pyrometry for temperature measurement in gas flames

Multi-wavelength pyrometry (MWP) has been used to measure the temperature of gas flames in a physical mock-up of an industrial burner. Even if pyrometric measurements of flame temperatures are difficult on account of the very low emissivity of gases, a self emitted radiation at defined wavelengths (590nm, 672nm, 766nm and 771nm) was detected from the different spectrums. The flame temperature can be obtained by processing the values of the ratio of two detected signals with the two-colour pyrometry procedure. A good correspondence was found between the temperature deduced from this ratio and the one measured by a type K thermocouple.