Emerson Rosemount 5600 Series, Reference Manual

Page: 77 / 128

77
Reference Manual
00809-0100-4024, Rev CA
Configuration
March 2020
Configuration
Close Distance Window
This parameter defines a window centered at the current surface position in which
new surface echo candidates can be selected. The size of the window is
± CloseDist.
Echoes outside this window will not be considered as surface echoes. The
transmitter will immediately jump to the strongest echo inside this window.
If there are rapid level changes in the tank, the value of the Close Distance Window
could be increased to prevent the transmitter from missing level changes. On the
other hand, a value too large might cause the transmitter to select an invalid echo
as the surface echo.
Double Bounce Possible
Some radar waves are reflected against the tank roof and back to the surface
before they are detected by the transmitter. Normally, these signals have a low
amplitude and are therefore neglected by the transmitter. For spherical and
horizontal cylinder tanks, in some cases the amplitude may be strong enough to
lead the transmitter to interpret the double bounce as the surface echo. By setting
the Double Bounce parameter this type of measurement situation may be
improved. This function should only be used if the problem of double bounces can
not be solved by changing the mounting position.
Actual level
Virtual level. After the signal is
mirrored in the product surface
and the roof, this level may be
presented as actual level.