Application Challenges; Handling Disturbances At Top Of Tank - Emerson Rosemount 5408 Reference Manual

Service and Troubleshooting
November 2017
7.6

Application challenges

7.6.1

Handling disturbances at top of tank

There are two general methods for managing disturbance echoes at the top of the tank:
Set amplitude threshold section

Extend the Upper Null Zone

Set amplitude threshold section
If necessary, a customized amplitude threshold section can be used to block out disturbing echoes (e.g.
from the tank nozzle or bypass well inlet). Refer to
guidelines.
Process seal antenna
Amplitude threshold sections are pre-configured at the factory for transmitters with process seal
antenna. For nozzles taller than 10 in. (25 cm), it may be necessary to manually increase the distance
value for the first endpoint
1. In Rosemount Radar Master Plus, start the echo curve reading, see
2. View the echo curve plot to find out if there are disturbing echoes close to the transmitter.
3. Calculate the required distance to the first endpoint.
Distance = Nozzle height + 2 in. (50 mm) =
4. In the echo curve, click the first endpoint and type the calculated value
5. Select Save.
Figure 7-9. First Endpoint
A. First endpoint
106
"Set amplitude thresholds" on page 96
(Figure 7-9).
00809-0100-4408, Rev BA
"Use the echo curve" on page
(Figure
A
Reference Manual
for general
92.
7-9).
Service and Troubleshooting