IMPAC Infrared sensor IN 2000
10
7.7
Clear time of the maximum value storage (tClear)
If the maximum value storage is switched on always the highest last temperature value
will be displayed and stored. The storage has to be cleared at regular intervals for
exchanging 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:
At clear time “off“ the max. value storage is switched off and only momentary values are meas-
ured.
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.
auto:
The “
auto
” mode is used for discontinuous measuring tasks. For example objects are trans-
ported on a conveyer belt and pass the measuring beam of the pyrometer only for a few sec-
onds. Here the maximum value for each object has to be indicated. In this mode the maximum
value is stored until a new hot object appears in the measuring beam. The temperature which
has to be recognized as “hot“ is defined by the low limit of the adjusted sub range. The stored
maximum value will be deleted when the temperature of the new hot object exceeds the low
limit “
from
“ of the sub range by 1% or at least 2°C. If a lower limit is not entered, the maximum
value storage will be deleted whenever the lower level of the full measuring range has been ex-
ceeded.
Note:
The maximum value storage follows the function of adjustment of exposure time.
This results in:
clear time
the adjusted response time is useless
clear times must be at least 3 times longer than the response time
only maxima with full maximum value can be recorded, which
appear at least 3 times longer than the response time.
7.8
Analog output (mA)
The analog output has to be selected according to the signal input of the connected
instrument (controller, PLC, etc.).
7.9
Subrange (from / to)
You have the opportunity to choose a subrange (minimum 51°C) within the basic temperature range of the
pyrometer. This subrange corresponds to the analog output. “
from
“ describes the beginning of this tempera-
ture range, “
to
“ the end of the range.
Additionally with the setting of a subrange it is possible to fulfill the requirements of the “auto” clear mode of
the maximum value storage (see above).
7.10
Ambient temperature compensation
The compensation of the ambient temperature can be used at low measuring tempera-
tures (below 100°C). This compensation is used for a very few special applications only.
The standard setting of this parameter is “auto”, because the temperature of the air
around the pyrometer is normally the ambient temperature of the measured object.
Should the measured object be placed in an area with a higher wall temperature (e.g.
inside a furnace), the measurement might be falsified (probably too high temperature indication). This influ-
ence can be compensated by presetting of the ambient temperature of the object (presetting within the
measuring range of the instrument).
After switching over to “man” the corresponding data field T(amb) is activated so that the ambient tempera-
ture value can be entered.
It has to be considered, that this method only improves the results if the ambient temperature
at the place of the measured object is always constant and the emissivity is well known.
Settings:
off
0.1 s
. . .
25 s
auto
Set to:
4 ... 20 mA
Settings:
auto
-32°C (-25,6°F)
. . .
900°C (1652°F)