User manual

Operating Instructions OPUS20E For external sensors
11
EN
9
.4. Using the Alarm Hysteresis
If you use the alarm function with an alarm hysteresis, the alarm will be trig-
g
ered and recorded every time the alarm thresholds are exceeded.
If the corridor between the selected alarm thresholds is very narrow, the alarm
will be triggered more often.
If, for example, you have selected 24°C as your upper alarm threshold for the
room temperature and 10°C for your lower alarm threshold and the room tem-
perature fluctuates between 23.5 and 25°C during the entire measuring period,
then this would lead to the alarm being triggered and recorded much more often
than would perhaps otherwise be the case during a normal measuring period.
In order to prevent this from happening, you can set an alarm hysteresis. By
doing so you are defining a value which has to be reached in the selected value
corridor, the so-called “good sector” to switch off the alarm.
The alarm hysteresis is set to 1°C in the previous example. This means that the
alarm will be triggered when the measured value has exceeded 24°C and then
switched off again when it reaches 23°C.
10. Cleaning and Maintenance
Instructions
10.1. Replacing the Batteries
When the message “LO bAtt” appears on the display,
the batteries have to be replaced.
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The data logger cannot log data while the batteries are being
replaced. If you have to interrupt a logging process, please ensure
that the data logger is set to operating mode M1 or M2 before the
batteries are replaced.
Open the battery compartment and remove the used batteries. Place the new
batteries in the battery compartment. Make sure that the poles are properly
aligned.
The clock continues to give the correct time for at least a minute while the
batteries are being replaced.
HYSTERESIS
Alarm display without hysteresis
Alarm display with hysteresis
Logging mode
Logging mode
U
pper alarm
threshold value
S
et value
c
orridor –
“Good sector”
Lower alarm
threshold
value
Flashing
Static
Upper alarm
threshold value
Set value
corridor –
“Good sector”
Lower alarm
threshold
value
Flashing
Static
Only use batteries which are permissible according to the technical specifications.
Other battery types can cause faults. Do NOT use rechargeable batteries.
Do NOT dispose of used batteries in your household waste. Do NOT throw into
an open fire or water. Please dispose of these batteries in a proper manner in
accordance with existing regulations.
10.2. Installation During Mobile Operation
The data logger can be placed at any random position during mobile operation.
Please make sure that the permissible ambient conditions are observed
(see Technical Data). Because of its compact size, the data logger can be easily
concealed during mobile operation.
10.3. Mounting the Logger on a Wall
If stationary logging is to be carried out, the data logger can be mounted on a
wall or fixed to a mounting rail. A mounting rail is included in the scope of
delivery.
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The wall mount must be used if the logger is being used in
network operation. You will find more information on
network operation in chapter 6.2.2.
10.4. Changing Locations
A change of location, i.e. from a cold to a warm place (for example when the de-
vice has been left in a car overnight before being brought into a warm room for
measuring), can lead to condensation forming on the printed circuit board.
This physical phenomenon, which cannot be avoided through any change in the
construction of such a measuring device, will invariably lead to incorrect readings.
Please wait approximately 5 minutes to give the device enough time to adapt to
its new surroundings before carrying out measuring.