Emerson Rosemount 5408, Reference Manual

Page: 134 / 274

7.5.2 Tracking of weak surface echoes close to tank bottom
Use tank bottom projection
The Tank Bottom Projection function can be used to enhance measurement performance
in the tank bottom region.
If the product surface echo is weak in the tank bottom region and the bottom echo is
strong (typical for flat tank bottoms), the transmitter may lock on the bottom echo and
report a false level measurement (empty tank). If the application requires, the Tank
Bottom Projection settings can be user-defined.
Figure 7-11 illustrates an example of the
Tank Bottom Projection when the tank is being emptied.
Figure 7-11: Tank Bottom Projection
%
& '
$ $
%
A. Level
B. Time
C. Enabled
D. Disabled
Procedure
1. In Rosemount Radar Master Plus, under Configure , select Level Setup
→
Advanced .
2. Under More Advanced Options , select Empty Tank Handling .
3. In the
Tank Bottom Projection
list, select
Enabled
or
Disabled
.
4. If you enabled Tank Bottom Projection, then:
a) Set the Bottom Product Dielectric Constant.
b) Enter Maximum Projection Distance.
c) Enter Minimum Tank Bottom Echo Amplitude.
5. Select Save .
Bottom product dielectric constant
Enter the product dielectric constant for the product in the bottom of the tank.
Maximum projection distance
This defines the range in which the function operates. Enter the maximum distance from
the zero level (tank bottom). It is recommended to use the default setting.
Service and troubleshooting Reference Manual
February 2020 00809-0100-4408
134 Reference Manual