Multiwavelength pyrometry: Radiance temperature versus wavelength curve should be used for temperature determination

Abstract

In multiwavelength pyrometry it is very difficult to represent the wavelength variation of emissivity so that a "correct" blackbody temperature T0 is obtained. On the other hand, use of T r's, the radiance temperature, permits the calculation of the blackbody temperature T0. In all cases studied up to now, in the wavelength range 0.4-4 μm, we have a linear relationship between T r and L, the wavelength, Tr = Tlin - hL, where Tlin is the calculated blackbody temperature.