Infrared thermographic measurement of the surface temperature and emissivity of glossy materials

Abstract

Determination of the surface temperature and emissivity of glossy materials is a complicated task due to the relatively wide range of emissivity values and the reflection of infrared radiation from surrounding objects. As a consequence, standard methods used in infrared thermography are not applicable. In this article, an alternative method is proposed for the measurement of the surface temperature and emissivity of glossy materials used in the external structures of buildings that is based on an external source of thermal radiation. It is shown that the method gives quite accurate values of emissivity of both low- and high-emissivity glossy materials, whereas the surface temperature of low-emissivity glossy materials is less accurate and strongly depends on the accuracy of the used thermal camera.