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5.4.1.
Gauge operating logic when the reflection is lost
The medium reflection pulse is usually lost when the level is at the top dead zone or near the bottom of the tank. The diagram below shows the action taken by the
gauge depending on where the reflection was lost the last time.
During “EView2” polling the active “Device status” window function (or the “markers” diagram) must be used in order to follow the measurement status of the device
(to activate the function, see section 5.1.2.3).
1
2
3
4
Zone 1: Dead and detection delay zones
Marker “Tank full” and “Level lost” is displayed when
the medium enters the dead zone and no reflection is found.
This will also occur when the level reflection is within the detection delay zone.
The gauge assumes the tank is full and displays the maximum level value.
The gauge searches for a reflection along the entire length of the probe.
Zone 2: Full zone (and dead zone)
Marker “Tank full” is displayed in this zone.
If the gauge loses the signal in this zone, it reacts as in zone 1:
the tank is assumed to be full.
The gauge searches for a reflection along the length of the probe.
Zone 3: Central measurement zone
The gauge searches along the length of the probe for the largest pulse reflection.
If the pulse is lost the reading freezes at the last value.
Marker “Level lost” will be displayed.
Zone 4: Empty zone
If the reflection is lost here, the gauge assumes the tank is empty and marker “tank empty” is displayed.
The gauge searches for a reflection in this zone but makes a search along the entire length of the probe
every minute.
The reading will remain frozen during this time.
The short circuit reflection will become larger than the medium reflection at this time.