Aspects of thermal infrared diagnostics of grouped objects exposed to open atmospheric space

Infrared cameras are the basic measurement tool used to examine the quality of thermal insulation of various objects, especially building walls. However, the infrared camera measurement result is very sensitive to the correct adjustment of emissivity values of tested surface and radiative ambient temperature of considered object. The radiative ambient temperature of tested objects is the second parameter after the emissivity of examined surface in terms of the impact on the measurement result. In the case of measurements in open atmospheric space, for the simplest case, the surroundings of an object located in such space consist of the ground surface and a hypothetical hemispherical surface of the sky. The problem is more complex in the case of thermovision diagnostics of objects located in close proximity to other similar objects (for example, buildings located in dense housing estates). The work proposes a solution to the problem of determining the ambient radiation temperature of such objects, especially its vertical differentiation along the external walls of buildings. This phenomenon was observed during infrared camera inspections of relatively tall buildings in housing estates. Sample useful diagrams have been developed for selected examples. A calculation example has been prepared and shown.