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6.5 Specials Attentions
•
If the surface to the measured is covered by frost
or other material, clean it to expose the surface.
•
If the surface to be measured is highly reflective,
apply masking tape or finish black paint to the sur-
face.
•
If the meter seems to be giving incorrect readings
check the front cone. There may be condensation
or debris obstructing the sensor; clean per in-
struction in the maintenance section.
6.6 Emissivity Table
We listed below a few emissivities about some sur-
faces:
Substance
Emissivity
Asphalt
0.9 to 0.98
Concrete
0.94
Cement
0.96
Sand
0.90
Earth
0.92 to 0.96
Water
0.92 to 0.96
Ice
0.96 to 0.98
Snow
0.83
Glass
0.90 to 0.95
Ceramic
0.90 to 0.94
Marble
0.94
Plaster
0.80 to 0.90
