Tungsten Filament Emissivity Behavior
Ralph A. Felice
FAR Associates, 1532 Newport Drive, Macedonia, OH 44056
Abstract. The emissivity of tungsten wire filaments in incandescent lamps is widely known to change with wavelength. It is not so widely known that lamps initially exhibiting this behavior can change to greybody behavior during their lifetime. This complicates both predicting lamp behavior and measuring filament temperature.