Experiments were first conducted to measure the spectral intensity values under an open-air heating system and a high-vacuum heating system. Eight emissivity models were used to examine the multispectral radiation thermometry (MRT) in order to understand the effect of surface oxidation on temperature determination and find the best MRT emissivity model as well. Emissivity spectra are found similar in shape but not in magnitude under oxidized and unoxidized conditions. Surface oxidation causes the increase in emissivity and the difference at varied temperatures. Overall, one model shows the highest accuracy in temperature prediction for oxidized and unoxidized aluminum alloys. (C) 2011 Elsevier Ltd. All rights reserved.