Opal DT-8862, Manual

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③
Steam, dust, smoke, etc., Can prevent accurate measurement
by obstructing the unit’s optics.
z
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,
cove 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
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