2. Click again on one of the amplitude threshold points and select
Save
.
Suppressing false echoes
Stationary objects with horizontal surfaces may generate strong false echoes. When the
surface is close to an obstruction in the tank (e.g. beams and agitators), the surface and
false echoes might interfere and cause a decrease in performance.
However, false echoes can be suppressed to reduce the influence of such objects, in case
they cannot be totally avoided. When the surface is passing by a disturbing object, the
transmitter will then measure with higher reliability, even if the surface echo is weaker
than the false echo, see
.
Figure 7-20: Suppression of False Echoes
meter
0
0
1 000
2 000
3 000
4 000
5 000
6 000
7 000
mV
0.5
1.0
1.5
2.0
2.5
3.0
3.5
D
B
A
E
C
A. Amplitude threshold
B. Disturbing object
C. False echo suppression
D. Suppressed echo
E. Surface
Add a new false echo suppression
Prerequisites
Follow these recommendations before suppressing new false echoes:
•
Make sure a correct amplitude threshold is set.
•
Make sure the level is stable. A fluctuating level may indicate a temporary disturbance
which is not due to an interfering object.
Service and troubleshooting
Reference Manual
September 2022
00809-0100-4418
96
Emerson.com/Rosemount