Appendix A: Technical reference
A.2 Echo processing
SITRANS LR250 (PROFIBUS PA)
Operating Instructions, 08/2014, A5E32221386-AC
237
Auto False Echo Suppression Range (2.5.10.2.)
Auto False Echo Suppression Range specifies the range within which the learned TVT is
applied. Default TVT is applied over the remainder of the range.
The learned TVT screens out the false echoes caused by obstructions. The default TVT allows
the material echo to rise above it.
Auto False Echo Suppression Range must be set to a distance shorter than the distance to the
material level when the environment was learned, to avoid the material echo being screened out.
Example before Auto False Echo Suppression
①
default TVT
⑤
high calibration point = 0
②
false echo
⑥
obstruction at 1.3. m
③
material echo
⑦
material level at 3.2 m
④
sensor reference point