Emissivity And Ir Measurement Theory; Emissivity Factors For Common Materials - Craftsman 81998 Owner's Manual

Emissivity and IR Measurement Theory

IR Thermometers measure the surface temperature of an object.
The thermometer's optics sense emitted, reflected, and
transmitted energy. The thermometer's electronics translate the
information into a temperature reading which is then displayed
on the LCD.
The amount of IR energy emitted by an object is proportional to
an object's temperature and its ability to emit energy. This ability
is known as emissivity and is based upon the material of the
object and its surface finish. Emissivity values range from 0.1 for
a very reflective object to 1.00 for a flat black finish. For the
Model 81998, the emissivity is adjustable from 0.1 to 1.00. Most
organic materials and painted or oxidized surfaces have an
emissivity factor of 0.95. When in doubt, set the emissivity to
0.95.

Emissivity Factors for Common Materials

Material
Asphalt
Concrete
Cement
Sand
Soil
Water
Ice
Snow
Glass
Ceramic
Marble
Plaster
Mortar
Brick
Emissivity
0.90 to 0.98
0.94
0.96
0.90
0.92 to 0.96
0.92 to 0.96
0.96 to 0.98
0.83
0.90 to 0.95
0.90 to 0.94
0.94
0.80 to 0.90
0.89 to 0.91
0.93 to 0.96
Material
Cloth (black)
Skin (human)
Leather
Charcoal (powder)
Lacquer
Lacquer (matt)
Rubber (black)
Plastic
Timber
Paper
Chromium Oxides
Copper Oxides
Iron Oxides
Textiles
15
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