Process Sensors Sensor Therm METIS M311 Operating Manual page 28

oriented measurements. They can
vary due to material-dependent condi-
tions, as in metals additionally to the
surface 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 correct emis-
sivity also a comparison measure-
ment can be performed with a ther-
mocouple).
 "n.s." (not specified) means that no
values exist for this wavelength
range e.g. because a reasonable
measurement in this wavelength or
temperature range is not possible.
 The emissivities with "shiny" refer to
applications that are performed un-
der an inert gas or in a vacuum.
Measurement deviations at a 10% false set emissivity
Materials has a maximum emissivity of 1 (100%). However, a setting of up to 1.2 can be used to compensate
for temperature corrections due to higher background reflection.
To determine the correct emissivity, also a comparative measurement with a thermocouple can be performed.
|INFO|
Emissivity, transmittance and spot size fill factor are directly related to each other, the result of the mul-
tiplication of the 3 parameters has to be minimum 5%. If the multiplication of the 3 parameters falls below 5%,
the values are displayed in red in the SensorTools control window (see 7.3.1).
6.2.6 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.
|INFO|
Emissivity, transmittance and spot size fill factor are directly related to each other, the result of the mul-
tiplication of the 3 parameters has to be minimum 5%. If the multiplication of the 3 parameters falls below 5%,
the values are displayed in red in the SensorTools control window (see 7.3.1).
6.2.7 Spot Size Fill Factor
Entering a fill factor that indicates how much percent of the measuring field is filled, has no influence if using
the 2-color measuring mode (see also
In 1-color mode: Measurements of objects that are smaller than the pyrometer's spot size can be performed
when measuring hot objects in front of a cold background. In this case the fill factor specifies how much per-
cent the measuring field is filled.
|INFO|
Emissivity, transmittance and spot size fill factor are directly related to each other, the result of the mul-
tiplication of the 3 parameters has to be minimum 5%. If the multiplication of the 3 parameters falls below 5%,
the values are displayed in red in the SensorTools control window (see 7.3.1).
28
Porcelain, glazed
Porcelain, rough
Platinum
Soot
Chamotte
Slag
Silver, shiny
Silver, oxidized
Steel, shiny
Steel, oxidized
Steel, rolled
Stoneware, glazed
Stainless steel
Titanium, shiny
Titanium, oxidized
Tungsten, shiny
Tungsten, oxidized
Brick
Zink
at a temperature of 700°C:
5.4 Alignment to the Measuring Object).
METIS M311 / M322 / H311 / H322 (12-pin)
0.6
0.8-0.9
0.4
0.95
0.45-0.6
0.85
n.s.
0.1-0.2
0.4-0.55
0.8-0.9
0.8-0.9
0.86-0.9
0.4-0.9
0.35-0.45
0.55-0.85
0.3-0.4
0.7-0.9
0.85-0.9
0.45-0.58
+10% 6.5°C
-10% 7°C
0.6
0.8-0.9
0.35
0.95
0.45-0.6
0.8-0.85
n.s.
0.05-0.2
0.3-0.45
0.7-0.9
0.8-0.9
0.8-0.9
0.4-0.9
0.3-0.4
0.55-0.85
0.3-0.4
0.7-0.85
0.8-0.9
0.45-0.55
10.5°C
11.5°C