LumaSense Technologies IS 50-LO plus - Manual (Page 22)

IS 50-LO plus / IGA 50-LO plus Manual Parameter descriptions / settings 22
5.2 Exposure time (t
90
)
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. In the “min” position, the
device operates using its time constant of < 1 ms.
Longer exposure times can be used for the measurement of objects which
have rapidly fluctuating temperatures to achieve constant temperature reading.
5.3 Clear time of the maximum / minimum value storage
(t
Clear
)
The integrated maximum value storage is activated when the parameter t
clear
is set to something other than “OFF” or “HOLD”.
If the maximum value storage is switched on, the highest last temperature
value will always be displayed and stored. As such, it may be beneficial to
periodically clear and reset the stored maximum values in order to obtain
new temperature readings.
This storage also has to be cleared at regular intervals when fluctuating
object temperatures cause the display or the analog outputs to change too rapidly or when the
pyrometer is not constantly viewing an object to be measured.
The maximum value storage value has two different operating modes:
Single Storage: Single storage mode is used when you want to reset the stored value
using an external impulse via one contact closure from an external relay (such as between
two measured objects). The relay contact is connected directly to the pyrometer between
pins J and K. This mode allows a new value to be established after each impulse from the
reset signal. Single storage mode also comes into effect when the Clear Peak Memory t
clear
is set to AUTO.
Double Storage: Double storage mode comes into effect when selecting one of the reset
intervals. This mode utilizes two memories. With the first memory, the highest measured
value is held and is deleted alternately in the time interval set (clear time). The other
memory retains the maximum value throughout the next time interval. The disadvantages
of fluctuations in the display with the clock frequency are thereby eliminated.
The following settings are possible:
Off: When set to OFF, the maximum value storage is switched off and all new temperature
values are measured but not stored.
0.01…25 s: If any clear time 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 of the storage can be activated and used within an own software
(see Chapter 9 Data format UPP (Universal Pyrometer Protocol)) or via an external contact (for
connection see 3.1.1 Pin assignment for the connector on the back of the pyrometer). In this
case, the storage operates only in single storage, because only a single deletion mechanism is
used.
auto: The auto mode is used for discontinuous measuring tasks. For example objects are
transported on a conveyer belt and pass the measuring beam of the pyrometer only for a few
seconds. Here the maximum value for each object has to be indicated. In this mode the
maximum value is stored until a new hot (or cold) 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
Settings:
0.01 s
0.05 s
0.25 s
1 s
3 s
10 s
Settings:
off
0.01 s
...
25 s
extern
auto
Hold