Exposure Time T - LumaSense Technologies IMPAC IN 5 plus Betriebsanleitung

IMPAC pyrometers series IN 5 plus
Measuring object
"Black body furnace"
Human skin
Black dull varnish
Carbon soot
Wood
Paper
Asphalt
Glass / quartz glass
Textile
Graphite
Cement
Water
Measuring object
Glass / quartz glass
One way to determine an accurate emissivity value for a material is to make a comparison measurement as
follows: If possible, coat a portion of the object with dull black paint or carbon soot. Paint and carbon soot
have high emissivities (95%) and take on the same temperature as the object. Measure the temperature of
the painted area with the emissivity control set to 95%. Then measure the temperature of an adjacent un-
painted area of the object and adjust the emissivity until the pyrometer displays the same temperature.
Setting examples at the instrument:
If the settings directly at the pyrometer should be used the pyrometer must be switched into offline mode
(OFFL, see 8.2). To adjust the emissivity via software see section 10, Settings via interface / software).
Note: If the emissivity is set to a incorrect value (below 20%) the instrument will
automatically utilize an emissivity value of 100%. The setting 00 is interpreted as
Emi = 100%.
9.1.2

Exposure time t

The exposure time is the time interval when the measured
temperature has to be present after an abrupt change so
that the output value of the pyrometer reaches a given
measurement value. The time taken is to reach 90% of the
recorded temperature difference. Slower response time can
be an advantage when trying to measure an object that has
a rapidly fluctuating temperature.
To change the exposure time the corresponding DIP switch
for 0.5 s, 1 s, 2 s or 5 s must be set in the ON position. A
longer response time of 10 s can be set if the switch for
0.5 s and 5 s is set to the ON position at the same time, a
longer response time of 30 s can be set if the switch for 1 s and 5 s is set at to the ON position the same
time. In the "OFF" position (Software InfraWin: t
technical data).
If the settings directly at the pyrometer should be used the pyrometer must be switched into offline mode
(OFFL, see 8.2). To adjust the exposure time via software see section 10, Settings via interface / soft-
ware).
Emi (at 8 ... 14 µm)
100%
98%
95%
95%
80 to 92%
92 to 95%
85%
72 to 87%
75 to 95%
75 to 92%
90%
95%
Emi (at 5.14 µm)
97%
Emi = 100%:
90
Measuring object
Brickwork
Fire clay
Rubber
Porcelain
Ceramics
Varnish
Plaster
Oil paint
Steel (oxidized)
Steel (smooth)
Aluminum (smooth)
Aluminum (anodized)
Setting examples at the instrument:
x10
Emi
0.5 s
1 s
2 s
5 s
4/0mA
ONL/OFFL
Example: t
= min), the device operates using its time constant (see
90
Emi (at 8 ... 14 µm)
85 to 95%
60 to 80%
10 to 30%
2 to 15%
90%
Emi = 85%:
x1 x10
Emi
0.5 s
1 s
2 s
5 s
4/0mA
ONL/OFFL
= 1 s Example: t
90
x1
= 5 s
90
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