Radiometry and Spectroscopy of Red Phosphorus Combustion Flames

Red phosphorus burns in a diffusion flame in air reaching temperatures up to just under T = 2500 K. The radiation of the flame in the infrared is not gray, but is mainly determined by emission bands of P4O10 and PO2 at  = 7.2; 10.1 and 13.3 µm causing a band ratio of 3-5 µm to 8-14µm of 3-5µm/8-14µm ~ 0.6 - 0.8.