Emerson Rosemount 5408 Reference Manual page 251

More advanced options
More advanced options are only available in Rosemount Radar Master Plus.
By default, these parameters are automatically set based on current configuration. It is
recommended that these parameters should remain at the default settings, unless there is
a good understanding of the function and capability of the parameters.
Empty tank handling
The Empty Tank Handling functions handle situations when the surface echo is close to the
tank bottom.
Table C-6:
Parameter
Empty tank detection area
Bottom echo visible when tank is empty
Tank bottom projection
The Tank Bottom Projection is used to enhance measurement performance near the
bottom of the tank. When the tank bottom echo is strong (typical for flat tank bottoms)
and the dielectric constant of the product is low (e.g. oil), the transmitter may lock on the
bottom echo and report a false level measurement (empty tank). This problem can be
solved by using the Tank Bottom Projection function. See
instructions.
Rosemount 5408 and 5408:SIS Level Transmitters
Empty Tank Handling
Configuration Parameters
Description
The Empty Tank Detection Area defines a range
where it is accepted to lose the echo from the
product. If the echo is lost in this range, the tank
is considered empty and the level is presented
as 0.
When the tank is empty, the transmitter looks in
this range for the product surface. When a new
echo is found in this range, it is considered to be
the product surface. Therefore, if there are dis-
turbance echoes in this area, they may need to
be filtered out.
This function requires the Bottom echo visible
when tank is empty parameter to be disabled.
Only enable this parameter if the bottom echo is
visible when tank is empty. By setting this pa-
rameter, the bottom echo will be treated as a
disturbance echo to facilitate tracking of weak
surface echoes close to the tank bottom (see
Enable bottom echo visible when tank is
Section 7.5.2
empty).
for further
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