Emerson Rosemount 5600 Series Reference Manual page 72

Configuration
March 2020
There are guidelines on when to register a false echo and what the Auto Configuration does.
Figure 4-2. Disturbance Echoes
Echo from disturbing
Surface echo
The False Echo function is used to improve the performance of the transmitter when the surface is close
to a horizontal surface of a stationary object in the tank. The object causes an echo when it is above the
surface. When the echoes from the surface and the object are close to each other, they might interfere
and cause a decrease in performance.
It is possible to store the positions of the disturbing objects in the memory of the transmitter. When the
surface is passing by a disturbing object, the transmitter can measure with a higher reliability, when the
position of the object is registered.
Use a spectrum plot to find the disturbance echoes. Remember to update it several times to get the
whole picture of disturbance echoes in the tank. Do not base the false echo registration on only one
updated spectrum plot. (See
Figure 4-3. Spectrum Plot for Typical Calm Conditions
2000 2000
1800 1800
1600 1600
1400 1400
1200 1200
1000 1000
800 800
600 600
400 400
200 200
0
0
A: General amplitude threshold
B: Amplitude threshold point (ATP)
C: Hold off distance (UNZ)
D: Echo curve
72
objects
Figure
C
B
P2 Unknown P2 Unknown
1.0 1.0 4.0 4.0
2.0 2.0 3.0 3.0
Disturbing objects
Surface
4-3).
D
A
5.0 5.0 6.0 6.0 7.0 7.0
Reference Manual
00809-0100-4024, Rev CA
8.0 8.0 9.0 9.0 10.0 10.0
Configuration