12. Emissivity
The emissivity of the product can be adjusted from 0.10 to 1.00 with the default value
of 0.95. Many common objects and materials (such as timber, water, skin and textile
fabric) can reflect the heat energy effectively. So it is easy to obtain relatively correct
measurement value. The emissivity is usually set as 0.95 when the coarse objects that
are easy to give out energy.
For semi-matte objects that give out less energy, the
emissivity is usually about 0.8. and the emissivity of semi-gloss objects is 0.6. The
shiny objects are divided into materials with low radiation coefficient. The emissivity
is usually set as 0.3 at the time of measurement.
Correct setting of the value of
emissivity is very important for you to carry out the most correct temperature
measurement. The surface emissivity will produce giant impact on surface
temperature measured by the product. Understanding the surface emissivity will
enable you to obtain correct temperature measurement result.
13. The Emissivity Value of Common
Materials
Substance
Thermal radiation
Substance
Thermal radiation
Bitumen
0.90-0.98
Black cloth
0.98
Concrete
0.94
Human skin
0.98
Cement
0.96
Foam
0.75-0.80
Sand
0.90
Charcoal dust
0.96
Earth
0.92-0.96
Paint
0.80-0.95
Water
0.92-0.96
Matte paint
0.97
Ice
0.96-0.98
Black rubber
0.94
Snow
0.83
Plastic
0.85-0.95
Glass
0.90-0.95
Timber
0.90
Ceramics
0.90-0.94
Paper
0.70-0.94
Marble
0.94
Chromium
hemitrioxide
0.81
Gypsum
0.80-0.90
Copper oxide
0.78
Mortar
0.89-0.91
Ferric oxide
0.78-0.82
Brick
0.93-0.96
Textile
0.90
