Operating Instructions

Auto False Echo Suppression (2.8.7.1.)
Used together with Auto False Echo Suppression Range (2.8.7.2.) to screen out false echoes
in a vessel with known obstructions. A ’learned TVT’ (time varying threshold) replaces the
default TVT over a specified range. See Auto False Echo Suppression (Page 228) for a more
detailed explanation.
Note
● Make sure material level is below all known obstructions when Auto False Echo
Suppression is used to learn the echo profile. (An empty or almost empty vessel is
recommended.)
● Note the distance to material level when Auto False Echo learns the environment. 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 instrument for best signal (lower false-echo
amplitude).
Before Auto False Echo Suppression
1
2
3
4
5
/HYHOGE
3URILOH>G%@
'LVWDQFH>P@
① TVT Hover Level ④ echo marker
② default TVT ⑤ material level
③ false echo
1. Determine Auto False Echo Suppression Range. Measure the actual distance from the
sensor reference point to the material surface using a rope or tape measure.
2. Subtract 0.5 m (20") from this distance, and use the resulting value.
3. Go to Auto False Echo Suppression Range (2.8.7.2.) and enter the value calculated in
step 2.
Parameter reference
SITRANS LR250 with mA/HART
126 Operating Instructions, 10/2019, A5E32220602-AG