Bartec R3 Series Operating Instructions Manual page 73

Annex
Emission factor
If you want to measure the temperature of an object without contact, you
need to know the emission degree "E" and include it in the measurements.
The calibration basis for IR temperature measuring units and control units is
the black body with the emission degree E = 1.
Determining the actual E factor
The emission factor depends on the material and the condition of its surface.
Theoretical values are specified in the corresponding literature.
Due to the fact that the E factor also depends on the wavelength, the
temperature and the direction in which the radiation is emitted, however, the
values listed in the table can only be used as rough approximates, for
instance for project planning. It can generally be said that raw, matt or
oxidized surfaces have a higher E factor than shiny materials.
Table showing the emission factor E at room temperature
Surface
Asbestos slate
Bakelite varnish
Lead, oxidized
Chrome nickel, oxidized 20 Ni 25 Cr 55 Fe
Chrome nickel, oxidized 20 Ni 25 Cr
Chrome nickel, oxidized 60 Ni 12 Cr 28 Fe
Roofing felt
Ice, smooth, water layer
Ice, rough surface
Enamel, white / porcelain
Iron, oxidized
Iron, oxidized
Iron, rusty
Iron, rolling skin
Plaster
Glass
Graphite
Rubber, soft, grey
Rubber, hard
Skin, dry
Radiator varnish, oil paint
Wood (beech)
Plastics (PVC, PTFE, PE at thicknesses of 0.4 mm
or more)
Copper, oxidized
Matt varnish, e.g. 3 M 1020
Brass, oxidized
Paper
Steel, raw
Clay, baked
Brick, mortar, plaster
Operating Instructions Radiation sensors R3XX
Temperature (°C) E factor
20 0.93
80 0.935
200 0.63
200 0.90
500 0.97
270 0.89
20 0.93
0 0.966
0 0.985
20 0.9...0.92
100 0.74
500 0.84
25 0.85
20 0.77
20 0.85
20...90 0.94
20 0.45
25 0.86...0.94
25 0.955
30 0.96
85 0.925
20...70 0.915
20...150 0.91
20...130 0.77
20...120 0.96
200...600 0.60
20 0.85
40...400 0.79...0.94
70 0.91
20 0.93
Annex
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