Figure 6-13: Echo Curve Before and After Trim Near Zone
$
$
&
%
A. Reference Peak
B. Trim Near Zone
C. 0-3.3 ft (0-1 m)
Use the Trim Near Zone function
The Trim Near Zone function is used to fine tune performance in the area close to the tank
top (Near Zone).
Prerequisites
Before performing the Trim Near Zone, ensure that:
•
There is product in the tank.
•
The product level is below the Near Zone region (0-3.3 ft (0-1 m) below the Upper
Reference Point).
Note
The Trim Near Zone function should only be used for reducing impact from stationary
disturbances. For occasional disturbances, use the Near Zone Threshold.
Procedure
1. Select
Service Tools
→
Echo Tuning
and click
Near Zone
.
2. Under
Near Zone Compensation
, select
Trim Near Zone
and follow the on-screen
instructions.
Change the upper null zone
Measurements are not performed within the Upper Null Zone (UNZ). The Upper Null Zone
can be extended to block out disturbing echoes close to the tank top, caused by for
example a narrow nozzle with rough walls, obstacles close to the probe, or a nozzle that
protrudes into the tank. See
.
Service and troubleshooting
Reference Manual
February 2020
00809-0100-4308
132
Rosemount 3308 Series
Summary of Contents for Rosemount 3308A
Page 8: ...Contents Reference Manual February 2020 00809 0100 4308 viii Rosemount 3308 Series ...
Page 10: ...Introduction Reference Manual February 2020 00809 0100 4308 10 Rosemount 3308 Series ...
Page 22: ...Transmitter overview Reference Manual February 2020 00809 0100 4308 22 Rosemount 3308 Series ...
Page 74: ...Installation Reference Manual February 2020 00809 0100 4308 74 Rosemount 3308 Series ...
Page 96: ...Configuration Reference Manual February 2020 00809 0100 4308 96 Rosemount 3308 Series ...