General interpolation equations for the calibration of radiation thermometers

Abstract

Many interpolation equations used in the calibration of radiation thermometers are semi-empirical in nature, providing little information on the characteristics of the thermometer. In this paper a systematic approach is taken in the derivation of two general interpolation equations, the first based on Wien's law and the second on Planck's law. Because these equations are based on physical principles they can be used with increased accuracy and confidence over semi-empirical equations, and their limitations are easily understood. The two general equations provide a framework for the development of specific equations for radiation thermometers and for the understanding of the relationships of interpolation equations to the effective wavelength formulation currently employed in radiation thermometry.