Appendix
58
Rev. A1 Jan 2015
3i Plus
Metals
Emissivity
Material
1 µm
1.6 µm
Monel (Ni-Cu)
0.3
0.2-0.6
Oxidized
Nickel
Oxidized
0.8-0.9
0.4-0.7
Electrolytic
0.2-0.4
0.1-0.3
Platinum
Black
0.95
Silver
0.02
Steel
Cold-Rolled
0.8-0.9
0.8-0.9
Ground Sheet
Polished Sheet 0.35
0.25
Molten
0.35
0.25-0.4
Oxidized
0.8-0.9
0.8-0.9
Stainless
0.35
0.2-0.9
Tin (Unoxidized)
0.25
0.1-0.3
Titanium
Polished
0.5-0.75
0.3-0.5
Oxidized
0.6-0.8
Tungsten
Polished
0.35-0.4
0.1-0.3
Zinc
Oxidized
0.6
0.15
Polished
0.5
0.05
Table 8: Typical Emissivity Values
To optimize surface temperature measurements, consider the following guidelines:
•
Determine the object emissivity using the instrument, which is also to be used for
measurements.
•
Avoid reflections by shielding the object from surrounding temperature sources.
•
For higher temperature objects use instruments with the shortest wavelength possible.
•
For translucent materials such as plastic foil or glass, ensure that the background is uniform
and lower in temperature than the object.
•
Hold instrument perpendicular to surface whenever emissivity is less than 0.9. In all cases, do
not exceed angles more than 30 degrees from incidence.
•
For 1M and 2M models, avoid measurements in high ambient light conditions.
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