Appendices; Emissivity Factors For Common Materials; Infrared Energy And Imaging Overview - FLIR TG165 User Manual

12 Appendices
12.1 Emissivity Factors for Common Materials
Material
Asphalt
Concrete
Cement
Sand
Soil
Water
Ice
Snow
Glass
Ceramic
Marble
Plaster
Mortar
Brick
12.2 Infrared Energy and Imaging Overview
A thermal imager generates an image based on temperature differences. In a thermal image the hottest item in
the scene appears as white and the coldest item as black, and all other items are represented as a gray scale
value between white and black.
It may take some time to get used to the thermal imagery. Having a basic understanding of the differences
between thermal and daylight cameras can help with getting the best performance from the TG165.
One difference between thermal and daylight cameras has to do with where the energy comes from to create an
image. When viewing an image with an ordinary camera, there has to be some source of visible light (something
hot, such as the sun or lights) that reflects off of the objects in the scene to the camera. The same is true with
human eyesight; the vast majority of what people see is based on reflected light energy. On the other hand, the
thermal imager detects energy that is directly radiated from objects in the scene.
FLIR TG165 USER GUIDE Document Identifier: TG165‐en‐US_AA
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Emissivity Material
0.90 to 0.98 Cloth (black)
0.94 Skin (human)
0.96 Leather
0.90 Charcoal (powder)
0.92 to 0.96 Lacquer
0.92 to 0.96 Lacquer (matt)
0.96 to 0.98 Rubber (black)
0.83 Plastic
0.90 to 0.95 Timber
0.90 to 0.94 Paper
0.94 Chromium Oxides
0.80 to 0.90 Copper Oxides
0.89 to 0.91 Iron Oxides
0.93 to 0.96 Textiles
Emissivity
0.98
0.98
0.75 to 0.80
0.96
0.80 to 0.95
0.97
0.94
0.85 to 0.95
0.90
0.70 to 0.94
0.81
0.78
0.78 to 0.82
0.90