Rosemount 5401, Справочное руководство

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Reference Manual
00809-0100-4026, Rev FA
July 2009
Rosemount 5400 Series
C-4
ADVANCED
TRANSMITTER
SETTINGS
Antenna Type
The transmitter is designed to optimize measurement performance for each
available antenna type.
This parameter is pre-configured at factory but may need to be set if a
non-standard antenna is used.
Empty Tank Handling
The Empty Tank Handling functions handle situations when the surface echo
is close to the tank bottom:
• Tracking of weak product echoes
• Handling lost echoes
If the surface echo is lost, this function has the transmitter present a zero-level
measurement. An alarm is activated unless the alarm has been blocked.
Empty Tank Detection Area
The Empty Tank Detection Area is the range within a lower limit of 16 in. (400
mm) and a higher limit of 39 in. (1000 mm) above the tank bottom. If the
surface echo is lost in this region, the tank is considered empty (the device
enters Empty Tank State), and the transmitter presents a zero level reading.
If the tank is empty, the transmitter searches double the Empty Tank Detection
Area for the product surface. When a new echo is found it is considered to be
the product surface.
It is important there are no disturbances in this area, but if there are, they may
need to be filtered out.
This function requires the Bottom Echo Visible function to be disabled. The
current Empty Tank Detection Area value is shown in Advanced Setup in
RRM and can be adjusted manually, if required. See “Empty Tank Detection
Area” on page C-8.
Bottom Echo Visible
Only set this parameter if the bottom echo is visible. Setting this parameter
will use the bottom echo as a disturbance echo to facilitate tracking of weak
surface echoes close to the tank bottom.
Check that the gauge detects the tank bottom when the tank is empty before
activating this function. See “Bottom Echo Visible” on page C-7.
Tank Bottom Projection
This function handles situations close to the tank bottom and may enhance
measurement performance in the tank bottom region. In this region the signal
from the actual tank bottom may be significantly stronger than the
measurement signal from the product surface, in some situations.
Extra Echo
Extra Echo Detection is used for tanks with domed or conical bottom types
and when there is no strong echo from the tank bottom when the tank is
empty and an echo beneath the actual tank bottom can sometimes be seen.
See “Extra Echo Function” on page C-9.