Effects of the temperature and roughness on the metal emissivity

An experimental apparatus was established by the combinational method of thermocouples and thermal imager for measuring the metal emissivity. The device consists of a heating system, a sample platform, a temperature detection system, a vacuum device and an infrared shielding mechanism. The emissivity of two different metals at different temperatures and roughness was measured by the apparatus. Research shows that, between 820 °C and 1010 °C, the emissivity of the metal increases with the increasing temperature and roughness; The effect of roughness on the emissivity is significant in low temperature, however, it is opposite in high temperature; The emissivity of Q235 steel is much greater than that of T2 copper at the same temperature and roughness; The emissivity relative errors of the rough surface of Q235 steel and T2 copper are 0.24% and 0.16%, respectively.