RayTek Thermalert ET Series Operator's Manual page 31

Material
Asbestos
Asphalt
Basalt
Carbon
Unoxidized
Graphite
Carborundum
Ceramic
Clay
Concrete
Cloth
Glass
Plate
"Gob"
Gravel
Gypsum
Ice
Limestone
Paint (non-al.)
Paper (any color)
Plastic (opaque,
over 20 mils)
Rubber
Sand
Snow
Soil
Water
Wood, Natural
To optimize surface temperature measurements consider the following guidelines:
1. Determine the object emissivity using the instrument to be used for the measure-
ment.
2. Avoid reflections by shielding object from surrounding high temperature sources.
3. For higher temperature objects use shorter wavelength instruments, whenever
overlap occurs.
4. For semi-transparent materials such as plastic film and glass, assure that the back-
ground is uniform and lower in temperature than the object.
5. Mount sensor perpendicular to surface whenever emissivity is less than 0.9. In all
cases, do not exceed angles more than 30 degrees from incidence.
A-4
Non-Metals
Emissivity
2.2µm
0.8
—
—
0.8-0.9
0.8-0.9
0.95
0.8-0.95
0.8-0.95
0.9
—
0.2
0.4-0.9
—
—
—
—
—
—
—
—
—
—
—
—
—
Thermalert ET Series Operator's Manual
5.1µm 8-14µm
0.9 0.95
0.95 0.95
0.7 0.7
0.8-0.9 0.8-0.9
0.7-0.9 0.7-0.8
0.9 0.9
0.85-0.95 0.95
0.85-0.95 0.95
0.9 0.95
0.95 0.95
0.98 0.85
0.9 —
0.95 0.95
0.4-0.97 0.8-0.95
— 0.98
0.4-0.98 0.98
— 0.9-0.95
0.95 0.95
0.95 0.95
0.9 0.95
0.9 0.9
— 0.9
— 0.9-0.98
— 0.93
0.9-0.95 0.9-0.95