METIS M308 / M309 / M313 / M316 / M318 / M323 / H309 / H316 / H318 (12-pin)
Configuring the Pyrometer
26
6.3.1 Response Time t
90
The response time specifies the time that the pyrometer requires to track 90% of a sudden temperature
change on the signal output.
The response time depends on the requirements of the respective measuring task and can be adjusted.
If a short response time is selected, the temperature measurement follows the actual temperature
curve accurately. Short setting thus allowing the detection of briefly occurring temperature peaks,
which occur especially in fast heating processes or fast moving samples.
At longer response times, the measurement signal is smoothed and average values for temperature
fluctuations are formed caused by the inertial measurement.
6.3.1.1 Dynamic Adaptation at Low Signal Levels
(only M3 devices)
At the beginning of the temperature range at high measurement speeds, the risk of measurement un-
certainty is given by signal noise. This is compensated by the pyrometer by automatically increasing the
response time at the beginning of the temperature range from 1 ms to 4, 8 and finally 16 ms.
6.3.2 Storage Mode Maximum Value Storage (Peak Picker) / Clear Time t
CL
The maximum value storage always records the highest value during a measurement and holds it until it
is deleted manually or automatically:
Off:
The maximum value storage is off and the instantaneous value is measured.
Clear externally:
The maximum value is cleared manually by an external button or machine contact
Configurable Inputs / Outputs
). The external clearing also
can be carried out with the command
lx
Communication via Serial Inter-
face / Interface Commands
).
Automatically:
The maximum value is cleared, if after a "cold break" a new hot measuring object ap-
pears in the measuring beam. "Cold break" means that the measuring temperature
must be below of the beginning of the temperature range. The "cold break" must cor-
respond to at least the length of the set response time.
Time 0.01…25 s:
Clears the maximum value after the specified time (
note:
At too long clear times im-
portant temperature information can be lost at sinking temperatures).
Trigger:
The maximum value is manually generated via an external button or machine contact,
as long as the trigger contact is active. The maximum value display appears after re-
leasing the button.
6.3.3 Emissivity
Ɛ
The emissivity indicates the radiation capacity of an object to be measured relative to a black body
source with the same temperature. To obtain correct readings, the emissivity must be taken into ac-
count in the measurement and adapted for the respective measuring material on the pyrometer.
In principle applies: to
measure metals in a short-
wavelength spectral range
as possible, as there the
emissivity is higher than in
the long-wave range.
The specified values are
guide values, which were
determined in the labora-
tory and confirmed in ap-
plication-oriented meas-
urements. They can vary
due to material-dependent
conditions, as in metals
additionally to the surface
Measuring object
Emissivity
Ɛ
(Epsilon)
M308/09
H309
M316
H316
M318
H318
M323
Black body source
1
1
1
1
Aluminum, shiny
n.s.
0.05-0.2
0.02-0.4
0.01-0.2
Aluminum, oxidized
n.s.
0.3-0.4
0.3-0.65
0.3- 0.5
Alu, sandblasted, rough
n.s.
0.4-0.5
0.4-0.7
0.3-0.5
Alu, black anodized
n.s.
0.9
0.9
0.8-0.9
Lead oxidized
n.s.
n.s.
0.2-0.7
0.4-0.7
Bronze
0.2-0.4
0.2-0.4
n.s.
n.s.
Iron, liquid
0.15-0.3
0.1-0.25
0.1-0.2
n.s.
Iron, shiny
0.3-0.4
n.s.
n.s.
0.2-
Iron, oxidized
0.7-0.9
0.65-0.85
0.6-0.8
0.5-0.75
Graphite
0.8-0.92
0.8-0.9
0.8-0.9
n.s.
Gold, shiny
0.02-0.05
0.02-0.05
0.02
0.02