User's Manual

Remote operation
7.1 Operating via SIMATIC PDM
SITRANS LR250 (PROFIBUS PA)
Operating Instructions, 01/2014, A5E32221386-AB
73
7.1.5.2
Auto false echo suppression
Note
•
Ensure material level is below all known obstructions when using Auto False Echo
Suppression to learn the echo profile. An empty or almost empty vessel is recommended.
•
Note the distance to material level when learning the echo profile, and set Auto False
Echo Suppression Range to a shorter distance to avoid the material echo being screened
out.
•
Set Auto False Echo Suppression and Auto False Echo Suppression Range during
startup, if possible.
•
If the vessel contains an agitator it should be running.
•
Before adjusting these parameters, rotate the device for best signal (lower false-echo
amplitude).
If you have a vessel with known obstructions, use Auto False Echo Suppression to prevent false
echo detection. This feature can also be used if the device displays a false high level, or the
reading is fluctuating between the correct level and a false high level.
The device learns the echo profile over the whole measurement range and the TVT is shaped
around all echoes present at that moment. See Auto False Echo Suppression (Page 207
) for a
more detailed explanation.
The learned TVT will be applied over a specified range. The default TVT is applied over the
remainder of the measurement range.