Elma 611B
side 19
Emissivity
Emissivity is a term used to describe the energy-emitting characteristics of materials.
Most (90% of typical applications) organic materials and painted or oxidized surfaces have an
emissivity of 0.95 (pre-set in the unit). Inaccurate readings will result from measuring shiny or
polished metal surfaces. To compensate, cover the surface to be measured with masking tape or flat
black paint. Allow time for the tape to reach the same temperature as the material underneath it.
Measure the temperature of the tape or painted surface.
Emissivity Values
Substance
Thermal emissivity
Substance
Thermal emissivity
Asphalt
0.90 to 0.98
Cloth (black)
0.98
Concrete
0.94
Human skin
0.98
Cement
0.96
Lather
0.75 to 0.80
Sand
0.90
Charcoal (powder)
0.96
Earth
0.92 to 0.96
Lacquer
0.80 to 0.95
Water
0.92 to 0.96
Lacquer (matt)
0.97
Ice
0.96 to 0.98
Rubber (black)
0.94
Snow
0.83
Plastic
0.85 to 0.95
Glass
0.90 to 0.95
Timber
0.90
Ceramic
0.90 to 0.94
Paper
0.70 to 0.94
Marble
0.94
Chromium oxides
0.81
Plaster
0.80 to 0.90
Copper oxides
0.78
Mortar
0.89 to 0.91
Iron oxides
0.78 to 0.82
Brick
0.93 to 0.96
Textiles
0.90
Maintenance
Repairs or service are not covered in this manual and should only be carried out by qualified trained
technician.
Periodically, wipe the body with a dry cloth. Do not use abrasives or solvents on this instrument.
For service, use only manufacturer’s specified parts.
