It has evolved into an important tool in building services, energy and environmental engineering. The visualisation of surface temperatures and the resulting heat flows are significant not only from a technical point of view, but can also be used to rapidly demonstrate energy flows and energy losses to laypersons. A great deal of experience and expertise is required to interpret a thermographic image accurately.
In thermography, the thermal radiation of a body is translated into a coloured image. To determine exact values with the aid of a thermal imaging camera, however, the emissivity of the surface must be known. A body with different surface structures has a large spread of values and so the radiation emitted can be different. The camera then images this in different colours.