Emerson Rosemount 5408 Reference Manual page 119

Reference Manual
00809-0100-4408, Rev BA
Change the upper null zone
The Upper Null Zone defines a zone close to the transmitter where echoes are ignored. This zone can be
extended to block out disturbing echoes at the top of the tank.
Note
Make sure the Upper Range Value (100%/20 mA) value is below the Upper Null Zone. Measurements are
not performed within the Upper Null Zone.
Figure 7-10. Upper Null Zone
A
100% (20 mA)
A. Upper Null Zone
B. Disturbance echo
C. Amplitude threshold
D. Product surface echo
Procedure
1. Identify desired Upper Null Zone using the echo curve plot.
a. In Rosemount Radar Master Plus, start the echo curve reading, see
b. View the echo curve plot to find out if there are disturbing echoes close to the transmitter.
2. Set the desired Upper Null Zone value.
a. Under Configure, select Level Setup > Antenna.
b. Under Advanced, type desired Upper Null Zone, and then select Save.
Service and Troubleshooting
B
C
0 1 000 2 000 3 000
page 92.
D
4 000 5 000 6 000 7 000
Service and Troubleshooting
meter
3.0
2.5
2.0
1.5
1.0
0.5
0
mV
"Use the echo curve" on
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