The emissivity and surface temperature of glossy materials are measured in IR thermography by covering the surface with a material with the known emissivity. The quantities can be, however, determined without using materials with the known emissivity. IR radiation is refl ected from the measured glossy surface and a thermographer detects such refl ection. This paper discusses the measurement of the surface temperature and emissivity of glossy materials which are used in external structures of the buildings -for instance, windows, light external walls or tiles. A four-point method is proposed for a more accurate determination of the surface temperature and emissivity of glossy materials. Results of successful laboratory and fi eld tests of the method are presented. Prinzipien der Vier-Punkt-Thermografi e-Messmethode für dieOberfl ächentemperatur und den Emissionsgrad glänzender Werkstoffe.

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.

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The statical securing of the building, where is situated on the mining area from the effect of hlubinného dobývání showes number strangeness. In addition to that, on top of The article deals with the issue of rehabilitation of statically substantial failures of churches and its static measures against future effects of undermining.template.

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