INTEGRATING SPHERE METHOD FOR DETERMINING THE EFFECTIVE SPECTRAL EMISSIVITY OF SUPERALLOYS AT HIGH-TEMPERATURES USING A SINGLE-WAVELENGTH PYROMETER

A method that employs an integrating sphere and a single-wavelength (1 .6-mu m) pyrometer for measuring the spectral effective emissivities o f superalloys in the temperature range (similar to 650 to 1050 degrees C) is described. The spectral effective emissivities for five superal loys, namely, MARM-247, MARM-509, CMSX-4, Inconel-718, and N-155 were measured. Correcting the pyrometer measurements for the variations in the object emissivity would reduce the uncertainty in the temperature measurements to <+/-1%. (C) 1996 Society of Photo-Optical Instrumentat ion Engineers.