Mapping of false refl ections lasts 5...30 sec.
according to the level meter type.
"MEDIUM TEMPERATURE" (Temperature compensation)
If the temperature of the measured substance (liquid) in the tank is different from the temperature where
the level meter is installed (see the mode "DIAGNOSTICS", p. 17), it is necessary to compensate the
temperature because of accuracy of the measurement. After the medium temperature is set, the level
meter calculates an average value (from the medium temperature and the temperature where the level
meter is installed) and uses this average temperature for calculation of the level position.
Inactive compensation (initial state), the word
"NO" appears on the display.
In case of installed mixers, it is necessary
to position the mixers under the level me-
ter (direct the mixer blade to the ultrasonic
signal beam).
Note: If there are
signifi cant obstacles
in
the upper half of the tank,
multiple false
refl ections
can occur especially in closed
tanks. In such cases it is necessary to
reduce the level in the tank as much se
possible to correctly mask these possible
multiple false re
fl
ections.
Fig. 17: The "Level distance" zone
1/2 tank
obstacles
Tolerance zone for "LEVEL
DISTANCE" value
NO ECHO: Current in case of echo loss (3.75mA)
DEAD ZONE: Dead zone current (22mA)
The values can be set in three steps - 3.75mA,
22mA and LAST (last measured data).
"FAILURE MODE" (Fault conditions)
It de
fi
nes the output current of the level meter when the measured medium level is in the dead
zone ("DEAD ZONE") or outside the measurement range in case of echo loss ("NO ECHO").
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