HEAT TRANSFER AND PYROMETRY

Harrison, T. R. Radiation Pyrometry and Its Underlying Principles of Radiant Heat Transfer (Wiley, New York, 1960). 

The transport of thermal energy can be broken down into one or more of three mechanisms conduction--heat transfer via atomic vibrations in solids or kinetic interaction amongst atoms in gases1 convection - - heat rapidly removed from a surface by a mobile fluid or gas and radiation—heat transferred through a vacuum by electromagnetic waves. The discussion will begin with brief explanations of each. These concepts are important background in the optical measurement of temperature (optical pyrometry) and in experimental measurement of the thermally conductive behavior of materials. 

Goldman, Y. "Gas Temperature Measurement in Gombustors by Use of Suction Pyrometry." in Heat Transfer in Furnaces, edited by C. Presser and D. G. Lilley,... 

We have developed a thermal approach based on a heat balance on a reference cylinder volume in the sample to evaluate the atomic oxygen recombination. The surface of this cylinder, 6 mm diameter and 3 mm height, represents the measurement area by pyrometry. Convective phenomena are neglected (rarefied gas flows) compared to the radiative fluxes to establish the equations for steady state heat transfer under different environments. The thermal balance is established under each atmosphere standard air, air plasma, standard argon and argon plasma, the determination of the recombination flux being done by difference between the experiments under air plasma (reactive) and ai on plasma (inert) [1, 2]. 

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