The Effect of Radiation Heat Transfer in the Measurement of Thermal Conductivity for the Semitransparent Medium

The effect of radiation heat transfer in the measurement of thermal conductivity for the semitransparent medium is examined, in general, as the parameters of the radiation conduction parameter, the optical thickness and the surface emissivity. The region where the superposition approximation of radiation and conduction can be applied is clarified, and then, the region where the radiation heat transfer can be neglected within an error of 5% and the region where the optically thick approximation can be applied within an error of 5% are clarified. Lastly, these examinations are applied to soda-lime glass.