ThinkIR: The University of Louisville\u27s Institutional Repository
Abstract
Two thermometer techniques for the determination of emissivities of surface coatings are presented. One procedure involving the attainment of steady state hear transfer relations in coated thermometers placed through the wall of a duct at right angles to the direction of air flow was found to give consistent results. Another procedure based upon the rate of change of thermometer temperature was found to give consistent results only with excellent control of air conditions. The emissivities of a variety of paints, varnishes and lacquers were determined for temperature range 90⁰ F. to 140⁰ F. using silver and black coatings for standardization. The results obtained by means of the static technique were more satisfactory
