SensorTherm METIS H3 series - Emissivity Values Table

METIS M308 / M309 / M313 / M316 / M318 / M323 / H309 / H316 / H318 (12-pin)
Configuring the Pyrometer
27
texture alloy components
play an important role for
the emissivity.
 Is a range given, this is
related to differences in
the nature of the sur-
face from smooth to
rough, rough surfaces
have higher emissivities
(for determining the cor-
rect emissivity also a
comparison measure-
ment can be performed
with a thermocouple).
 The emissivities with
"shiny" refer to applica-
tions that are performed
under an inert gas or in
a vacuum.
 “n.s.“ means that no
values exist for this
wavelength range (not
specified), e.g. because
a reasonable meas-
urement in this wave-
length or temperature
range is not possible.
Inconel, shiny
0.35-0.45
0.4
0.35
0.3
Inconel, oxidized
0.65-0.75
0.6-0.7
0.5
0.5
Copper, shiny
0.10
0.05-0.1
0.05
n.s.
Copper, oxidized
0.3-0.7
0.2-0.8
0.2-0.7
n.s.
Magnesium, shiny
n.s.
0.15-0.2
0.15-0.2
0.1-0.4
Magnesium, oxidized
n.s.
0.3-0.5
0.3-0.55
0.2-0.6
Brass, shiny
0.5-0.7
0.5-0.7
0.4-0.7
0.35-0.6
Brass, oxidized
0.6-0.8
0.6-0.7
0.5-0.6
0.5-0.6
Molybdenum, oxidized
0.7-0.9
0.7-0.85
0.65-0.8
0.6-0.7
Nickel
0.22
0.15-0.2
0.15-0.2
n.s.
Porcelain, glazed
0.6
0.6
0.6
n.s.
Porcelain, rough
0.8-0.9
0.8-0.9
0.8-0.9
n.s.
Platinum
0.4
0.35
0.35
0.3
Soot
0.95
0.95
0.95
n.s.
Chamotte
0.45-0.6
0.45-0.6
n.s.
n.s.
Slag
0.85
0.8-0.85
n.s.
n.s.
Silver, shiny
n.s.
n.s.
0.01
0.01
Silver, oxidized
0.1-0.2
0.05-0.2
0.05-0.2
0.05-0.25
Steel, shiny
0.4-0.55
0.3-0.45
0.3-0.4
0.25-0.4
Steel, oxidized
0.8-0.9
0.7-0.9
0.7-0.9
0.75-0.85
Steel, rolled
0.8-0.9
0.8-0.9
0.8-0.9
0.75-0.85
Stoneware, glazed
0.86-0.9
0.8-0.9
k.A.
n.s.
Stainless steel
0.4-0.9
0.4-0.9
0.4-0.9
n.s.
Titanium, shiny
0.35-0.45
0.3-0.4
0.3-0.4
n.s.
Titanium, oxidized
0.55-0.85
0.55-0.85
0.5-0.7
n.s.
Tungsten, shiny
0.3-0.45
0.3-0.4
0.15-0.25
n.s.
Tungsten, oxidized
0.7-0.9
0.7-0.85
0.65-0.85
0.5-0.7
Brick
0.85-0.9
0.8-0.9
n.s.
n.s.
Zinc
0.45-0.58
0.45-0.55
0.35-0.55
n.s.
Measurement deviations at a 10% false set
emissivity at a temperature of 700°C:
+10%
-6.5°C
-10.5°C
-12°C
-10%
+7°C
+11.5°C
+13°C
Measuring object
Emissivity M313
Wolfram under intert gas
0.35
Materials has a maximum emissivity of 1 (100%). However, a setting of up to 1.2 can be used to com-
pensate for temperature corrections due to higher background reflection.
To determine the correct emissivity, also a comparative measurement with a thermocouple can be per-
formed.
6.3.4 Transmittance
Is a viewing window located between measuring object and pyrometer, the transmittance of the window
must be considered during the measurement. Enter the transmittance of the window in order to obtain a
correct measurement result.
6.3.5 Spot Size Fill Factor
Measurements of objects that are smaller than the pyrometer’s spot size can be performed when meas-
uring hot objects in front of a cold background. In this case the fill factor specifies how much percent the
measuring field is filled (see also 5.4 Alignment to the measuring object).
INFO: Emissivity, transmittance and spot size fill factor are directly related to each other, the re-
sult of the multiplication of the 3 parameters has to be minimum 5%.