On the measurement of flame temperature and emissivity based on multispectral imaging technique

Abstract

Due to the low spatial resolution of spectrometer and low spectral resolution of CCD, a multi-wavelength radiation thermometry method employing multispectral imaging technology was proposed to measure flame temperature and emissivity. The calculated radiation intensity lines were obtained by the Hottel emissivity model and the least square method. The temperature and flame absorption capacity with the calculated spectral line closest to the measured spectral line were considered as the optimum results. The experimental results showed that maximum temperature of the flame was 1943 K appeared in the thin-wick paraffin. At any position, the emissivity of the thin-wick paraffin flame was lower than that of the thick-wick, but the emissivity of the biomass candle flame near the flame center was the highest. The measured temperature distribution was validated by employing a spectrometer system and the relative error was 2.66%.