Soot temperature and KL factor for biodiesel and diesel spray combustion in a constant volume combustion chamber

► Soot temperature and concentration of spray combustion measured using two color thermometry. ► Uncertainty of the technique was analyzed using statistical methods. ► Biodiesel produces lower soot than diesel. ► Soot temperature decreases with the decrease in ambient temperature. ► Biodiesel soot temperature is lower than diesel for 1000 K and 1200 K ambient.