Surface Temperatures and Temperature Measurement Techniques on the Level of Exposed Samples During Irradiation/Weathering in Equipment

Abstract

This chapter describes the surface temperature and temperature measurement techniques on the level of exposed samples during irradiation. Direct measurement of the surface temperatures of individual samples is not practical in weathering equipment. Therefore, one method that has been employed for quite some time during simulated weathering involves the measurement of the temperature of a “blackened, flat panel”, described as the “black panel temperature or BPT.” The effect of solar radiation on materials results in primary photochemical processes and secondary decomposition processes. The later are significantly influenced by other climatic parameters. Of these, the material-specific final surface temperature that is directly determined by the solar radiation has special significance. This chapter discusses the measurement techniques to characterize the surface temperatures of samples in weathering technology. The risk of an inadequate indication of surface temperatures of exposed materials inherent in the use of “random” black panel thermometers has been expounded in the chapter. The principle and design of the improved black standard thermometer (BST) measuring element have been indicated, and the systemic differences of the temperature values given by the BPT and BST have been discussed in the chapter.