Note on a New Blackbody Fraction Function Used for Surfaces With a Linear Emissivity in a Wavelength Interval

Abstract

In this note, a new blackbody radiation fraction function is proposed for calculating the emissive power or total emissivity of a surface that has an emissivity depending linearly on wavelength in a wavelength interval. This new fraction function is expressed as a function of the product of wavelength and temperature and the numerical values are tabulated. Based on the new defined fraction function, the emissive power in a given wavelength interval can be calculated very conveniently combined with the traditional blackbody radiation fraction function. This new function can be used in many practical applications with good accuracy without numerical integration.