LumaSense Technologies IGA 320/23 - Handbuch (Seite 11)

IMPAC pyrometer IGA 320/23
11
Measuring object
Emissivity [%]
(at 2.3 µm)
Measuring object
Emissivity [%]
(at 2.3 µm)
“Black body furnace“ 100 Steel, molten 20 to 30
Extruded Aluminum 13 Nickel 15 to 20
Brass 18 Titanium, non-oxidized 50
Brass oxidized (tarnished) 65 to 70 Titanium, oxidized 75 to 80
Copper 5 Molybdenum 10
Copper, oxidized 70 to 80 Molybdenum, oxidized 75 to 80
Inconel 30 Black Carbon 95
Inconel, oxidized 85 Graphite 80 to 90
Oxidized Iron 85 to 90 Stoneware, glazed 60
Steel rolling scale 80 to 88 Porcelain rough 80 to 90
6.6
Transmittance 
Using the close-up lens or measurements through windows slightly attenuates the measuring signal (due to
the transmittance). To get furthermore correct measuring results, the transmission of the close-up lens / win-
dow (90% for the close-up lens of the IGA 320/23) must be compensated. Alternatively the emissivity ε can
be adapted. For the close-up lens: ε
Trans
= 0.90 x ε
Object
6.7
EmiAutoFind
If the true temperature of the measured object is known, you can calculate the emissivity of the measured
object using the "Emi: AutoFind“ function (see software description 7.8 Measurement (color bar) –> Emi-
AutoFind).
6.8
Response time / exposure time (t90)
The exposure time is the time interval when the measured temperature has to be pre-
sent 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 differ-
ence. In the “min” position, the device operates using its time constant.
The dynamic exposure time adjustment prolongs the exposure time at the lower range
limit, also it t
90
is set to a lower value.
If the maximum value storage is selected and the measuring object has a low emissivity and the measuring
temperature is at the beginning of the range, a higher exposure time must be chosen to prevent measure-
ment errors. Longer exposure times can be used for the measurement of objects which have rapidly fluctuat-
ing temperatures to achieve constant temperature reading.
6.9
Clear time of the maximum / minimum value storage (tCL)
If the maximum value storage is switched on always the highest last temperature value
will be displayed and stored. The minimum value storage saves the lowest measure-
ment taken during a reading. The storage has to be cleared at regular intervals for ex-
changing by a new and actual value.
This feature is particularly useful when fluctuating object temperatures cause the dis-
play or the analog outputs to change too rapidly, or the pyrometer is not constantly
viewing an object to be measured. In addition, it may also be beneficial to periodically
delete and reset the stored maximum values.
The following settings are possible:
Off:
The max. value storage is switched off and only momentary values are measured.
0.01...25 s: If any clear time between 0.01 s and 25 s is set, the maximum value is estimated and held in
double storage mode. After the entered time the storage will be deleted.
extern: The external clearing can be activated and used within an own software and the clear command
“lx” (see section 11, Data format UPP). In this case, the storage operates only in single storage,
because only a single deletion mechanism is used.
Settings:
min
0.01 s
0.05 s
. . .
10.00 s
Settings:
off
0.01 s
. . .
25 s
extern
auto