The True Temperature Scale of an Oxide-Coated Filament

Following A. G. Worthing the spectral emissive power may be obtained from measurements of the reflection coefficient. This method is applicable to the oxide-coated filament both at room temperature and at normal operating temperatures. For a particular type of filament containing dispersed nickel the reflection coefficient averaged 36 percent independent of temperature and independent of the degree of activation, i.e., the content of free alkaline earth metal.