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Temperature measurement of aluminum surfaces by remote sensing of infrared radiation (pyrometry) is difficult due to the low and varying emissivity of aluminum. The emissivity of 1199 aluminum and 3004 and 5182 alloys was studied as a function of oxide level, surface roughness, temperature, and wavelength. Factorial analysis showed that oxide level and temperature were the major effects for the 1199 aluminum and 3004 alloy, while surface roughness and temperature were the major effects for the 5182 alloy. The emissivity curves indicated that the samples behave as grey bodies, except for samples with thick, high-temperature oxides, which exhibit metal oxide absorption bands in the 10–20 μm region of the emissivity curves. Repeatability in temperature measurement by pyrometry as a function of alloy was also studied. Alloy 5182 showed the greatest variability, followed by 3004 and 1199.

Temperature measurement of aluminum surfaces by remote sensing of infrared radiation is difficult because of the low and varying emissivity of aluminum. The variation in emissivity may be dependent on factors like surface roughness, surface oxides, temperature, or wavelength of the measurement. In order that the factors which affect the emissivity of pure aluminum might be studied, a specialized emission accessory was built to be used in conjunction with a Fourier transform infrared spectrometer. This paper describes the design of the accessory and presents emission spectra and emissivity curves demonstrating the accessory's capabilities.