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Reference Manual
00809-0100-4026, Rev HA
Appendix C: Advanced configuration
November 2014
Advanced Configuration
C.3.3 Full tank handling
Full tank detection area
This parameter defines a range where the surface echo can be lost. If the echo is lost in this
range, the tank is considered full (the device enters Full Tank State) and the device presents
maximum level indication.
When the tank is full, the device searches double the Full Tank Detection Area for the product
surface. When a new echo is found in this range, it is identified as the product surface.
It is important to filter out any disturbances in this area.
Level above hold off distance possible
This function should be enabled if the level can rise above the Hold Off Distance/UNZ and it is
necessary to display the tank as full in that case. Normally, the device will be able to track the
surface and the product level will never rise to that height. If the function is not enabled and the
surface is lost at the top of the tank, the device searches the whole tank for a surface echo.
Note
Measurements are not performed within the Hold Off Distance/UNZ region.
Level alarm is not set when tank is full
If the surface echo is lost, close to the top of the tank. The level value will normally be displayed
as “invalid.” This parameter should be set to suppress the “invalid” display.
Note
Setting this parameter disables the analog output so it does not enter alarm mode for invalid
levels close to the antenna.
See “Full tank handling” on page 247 for more information.
C.3.4 Double bounce
Some radar waves are reflected at the surface and then reflected against the tank roof and back
to the surface before being detected by the transmitter. Normally, these signals have a low
amplitude and are ignored by the transmitter. For spherical and horizontal cylinder tanks
however, the amplitude may be strong enough for the transmitter to interpret the double
bounce as the surface echo. Setting the Double Bounce Possible parameter can solve this type of
measurement situation. This function should only be used if double bounces cannot be
corrected by changing the mechanical installation. See “Double bounce” on page 248 for more
information.
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