Thermal imaging
Thermal imaging makes it possible to visualize temperatures and especially temperature distributions easily and quickly. For this, the infrared radiance of objects in certain frequency ranges is evaluated. Though thermal images are more or less self-explanatory, for a scientific interpretation of the images, the physical aspects of thermal images have to be taken into account. Besides the actual temperature, there is a strong influence of emission and reflection factor of the different materials on the heat radiation. This means that metallic surfaces have completely different radiation behavior than coated surfaces. However, thermal imaging is of great use for a lot of applications. The following examples will give an impression:

Thermal image of a closed deep freezer. Here occured temperatures below the dew point of the surrounding air on the glass. This made the glasses fog up.