Emissivity Charts and How Does Emissivity Effect Thermal Infrared Imaging
Using an objects radiation to measure its temperature is more difficult than attaching a thermometer or thermocouple to it, although sometimes this is the only convenient way. Other times, it is only necessary to see large area heat patterns, and this is difficult to do with a thermometer or thermocouple. In these cases a person can resort to any of a number of radiation measuring devices which will give a temperature indication (bolometers, pyrometers, thermopiles, line scanners, Infrared viewers, and thermographic systems)
Measurement consideration tips
- The way a surface appears in the visible is the way that surface will appear in the infrared as well.
- Get close enough for an object to occupy a sizable section of the IR camera screen, focus on the object
- Look at the object face on
- move around the object while scanning with the IR camera in order to eliminate reflections
- Try IR scanning on a windless day
- The higher the ambient temperature, the better the reading
- Watch out for the sun, for light, and for spectral absorption and emission.
Material |
Temperature (F) |
(C) |
E-Emissivity |
Adobe |
68 |
20 |
0.90 |
Asbestos |
|
|
|
Board |
100 |
38 |
0.96 |
Cement |
32-392 |
0-200 |
0.96 |
Cement, Red |
2500 |
1371 |
0.67 |
Cement, White |
2500 |
1317 |
0.65 |
Cloth |
199 |
93 |
0.90 |
Paper |
100-700 |
38-371 |
0.93 |
Slate |
68 |
20 |
0.72 |
Asphalt, pavement |
100 |
38 |
0.93 |
Asphalt, tar paper |
68 |
20 |
0.93 |
Basalt |
68 |
20 |
0.72 |
Brick |
|
|
|
Red, rough |
70 |
21 |
0.93 |
Gault Cream |
2500-5000 |
1371-2760 |
.26-.30 |
Fire Clay |
2500 |
1371 |
0.75 |
Lime Clay |
2500 |
1371 |
0.43 |
Fire Brick |
1832 |
100 |
.75-.80 |
Magnesite, Refractory |
1832 |
1000 |
0.38 |
Gray Brick |
2021 |
1100 |
0.75 |
Silica, Glazed |
2000 |
1093 |
0.88 |
Silica, Unglazed |
2000 |
1093 |
0.80 |
Sandlime |
2500-5000 |
1371-2760 |
.59-.63 |
Carborundum |
1850 |
1010 |
0.92 |
Ceramic |
|
|
|
Alumina on Inconel |
800-2000 |
427-1093 |
.69-.45 |
Earthenware, Glazed |
70 |
21 |
0.90 |
Earthenware, Matte |
70 |
21 |
0.93 |
Greens No. 5210-2C |
200-750 |
93-399 |
.89-.82 |
Coating No. C20A |
200-750 |
93-399 |
.73-.80 |
Porcelain |
72 |
22 |
0.92 |
White Al2O3 |
200 |
93 |
0.90 |
Zirconia on Inconel |
800-2000 |
427-1093 |
.62-.45 |
Clay |
68 |
20 |
0.39 |
” Fired |
158 |
70 |
0.91 |
” Shale |
68 |
20 |
0.69 |
” Tiles, Light Red |
2500-5000 |
1371-2760 |
.32-.34 |
” Tiles, Dark Purple |
2500-5000 |
1371-2760 |
0.78 |
Concrete |
|
|
|
Rough |
32-2000 |
0-1093 |
0.94 |
Tiles, Natural |
2500-5000 |
1371-2760 |
.63-.62 |
” Brown |
2500-5000 |
1371-2760 |
.87-.83 |
” Black |
2500-5000 |
1371-2760 |
.94-.91 |
Cotton Cloth |
68 |
20 |
0.77 |
Dolomite Lime |
68 |
20 |
0.41 |
Emery Corundum |
176 |
80 |
0.86 |
Glass |
|
|
|
Convex D |
212 |
100 |
0.80 |
Convex D |
600 |
316 |
0.82 |
Convex D |
932 |
500 |
0.76 |
Nonex |
212 |
100 |
0.82 |
Nonex |
939 |
500 |
0.76 |
Smooth |
32-200 |
0-93 |
.92-.94 |
Granite |
70 |
21 |
0.45 |
Gravel |
100 |
38 |
0.28 |
Gypsum |
68 |
20 |
.80-.90 |
Ice, Smooth |
32 |
0 |
0.97 |
Ice, Rough |
32 |
0 |
0.98 |
Lacquer |
|
|
|
Black |
200 |
93 |
0.96 |
Blue, on Al Foil |
100 |
38 |
0.78 |
Clear, on Al Foil (2 coats) |
200 |
93 |
.08 (.09) |
Clear, on Bright Cu |
200 |
93 |
0.66 |
Clear, on Tarnished Cu |
200 |
93 |
0.64 |
Red, on Al Foil (2 coats) |
200 |
93 |
.61 (.74) |
White |
200 |
93 |
0.95 |
White, on Al Foil (2 coats) |
100 |
38 |
.69 (.88) |
Yellow, on Al Foil (2 coats) |
100 |
38 |
.57 (.79) |
Lime Mortar |
100-500 |
38-260 |
.90-.92 |
Limestone |
100 |
38 |
0.95 |
Marble, White |
100 |
38 |
0.95 |
” Smooth, White |
100 |
38 |
0.56 |
” Polished Gray |
100 |
38 |
0.75 |
Mica |
100 |
38 |
0.75 |
Oil on Nickel |
|
|
|
0.001 Film |
72 |
22 |
0.27 |
0.002 “ |
72 |
22 |
0.46 |
0.005 “ |
72 |
22 |
0.72 |
Thick “ |
72 |
22 |
0.82 |
Oil, Linseed |
|
|
|
On Al Foil, uncoated |
250 |
121 |
0.09 |
On Al Foil, 1 coat |
250 |
121 |
0.56 |
On Al Foil, 2 coats |
250 |
121 |
0.56 |
On Polished Iron, .001 Film |
100 |
38 |
0.22 |
On Polished Iron, .002 Film |
100 |
38 |
0.45 |
On Polished Iron, .004 Film |
100 |
38 |
0.65 |
On Polished Iron, Thick Film |
100 |
38 |
0.83 |
Paints |
|
|
|
Blue, Cu2O3 |
75 |
24 |
0.94 |
Black, CuO |
75 |
24 |
0.96 |
Green, Cu2O3 |
75 |
24 |
0.92 |
Red, Fe2O3 |
75 |
24 |
0.91 |
White, Al2O3 |
75 |
24 |
0.94 |
White, Y2O3 |
75 |
24 |
0.90 |
White, ZnO |
75 |
24 |
0.95 |
White, MgCO3 |
75 |
24 |
0.91 |
White, ZrO2 |
75 |
24 |
0.95 |
White, ThO2 |
75 |
24 |
0.90 |
White, MgO |
75 |
24 |
0.91 |
White, PbCO3 |
75 |
24 |
0.93 |
Yellow, PbO |
75 |
24 |
0.90 |
Yellow, PbCrO4 |
75 |
24 |
0.93 |
Paints, Aluminium |
100 |
38 |
.27-.67 |
10% Al |
100 |
38 |
0.52 |
26% Al |
100 |
38 |
0.30 |
Dow XP-310 |
200 |
93 |
0.22 |
Paints, Bronze |
low |
low |
.34-.80 |
Gum Varnish (2 coats) |
70 |
21 |
0.53 |
Gum Varnish (3 coats) |
70 |
21 |
0.50 |
Cellulose Binder (2 coats) |
70 |
21 |
0.34 |
Paints, Oil |
|
|
|
All colors |
200 |
93 |
.92-.96 |
Black |
200 |
93 |
0.92 |
Black Gloss |
70 |
21 |
0.90 |
Camouflage Green |
125 |
52 |
0.85 |
Flat Black |
80 |
27 |
0.88 |
Flat White |
80 |
27 |
0.91 |
Gray-Green |
70 |
21 |
0.95 |
Green |
200 |
93 |
0.95 |
Lamp Black |
209 |
98 |
0.96 |
Red |
200 |
93 |
0.95 |
White |
200 |
93 |
0.94 |
Quartz, Rough, Fused |
70 |
21 |
0.93 |
Glass, 1.98 mm |
540 |
282 |
0.90 |
Glass, 1.98 mm |
1540 |
838 |
0.41 |
Glass, 6.88 mm |
540 |
282 |
0.93 |
Glass, 6.88 mm |
1540 |
838 |
0.47 |
Opaque |
570 |
299 |
0.92 |
Opaque |
1540 |
838 |
0.68 |
Red Lead |
212 |
100 |
0.93 |
Rubber, Hard |
74 |
23 |
0.94 |
Rubber, Soft, Gray |
76 |
24 |
0.86 |
Sand |
68 |
20 |
0.76 |
Sandstone |
100 |
38 |
0.67 |
Sandstone, Red |
100 |
38 |
.60-.83 |
Sawdust |
68 |
20 |
0.75 |
Shale |
68 |
20 |
0.69 |
Silica,Glazed |
1832 |
1000 |
0.85 |
Silica, Unglazed |
2012 |
1100 |
0.75 |
Silicon Carbide |
300-1200 |
149-649 |
.83-.96 |
Silk Cloth |
68 |
20 |
0.78 |
Slate |
100 |
38 |
.67-.80 |
Snow, Fine Particles |
20 |
-7 |
0.82 |
Snow, Granular |
18 |
-8 |
0.89 |
Soil |
|
|
|
Surface |
100 |
38 |
0.38 |
Black Loam |
68 |
20 |
0.66 |
Plowed Field |
68 |
20 |
0.38 |
Soot |
|
|
|
Acetylene |
75 |
24 |
0.97 |
Camphor |
75 |
24 |
0.94 |
Candle |
250 |
121 |
0.95 |
Coal |
68 |
20 |
0.95 |
Stonework |
100 |
38 |
0.67 |
Water |
100 |
38 |
0.67 |
Waterglass |
68 |
20 |
0.96 |
Wood |
low |
low |
.80-.90 |
Beech Planed |
158 |
70 |
0.94 |
Oak, Planed |
100 |
38 |
0.91 |