User's Manual
Table Of Contents
- 8 Parameter reference
- 9 Service and maintenance
- 10 Diagnosing and troubleshooting
- 11 Technical data
- 12 Dimension drawings
- 12.1 Threaded horn antenna
- 12.2 Threaded horn antenna with extension
- 12.3 Flanged horn antenna
- 12.4 Flanged horn antenna with extension
- 12.5 Flanged encapsulated antenna (2"/DN50/50A sizes only)
- 12.6 Flanged encapsulated antenna (3"/DN80/80A sizes and larger)
- 12.7 Threaded PVDF antenna
- 12.8 Threaded connection markings
- 12.9 Raised-Face flange per EN 1092-1 for flanged horn antenna
- 12.10 Raised-Face flange per EN 1092-1 for flanged encapsulated antenna
- 12.11 Flat-Face flange
- 12.12 Process connection tag (pressure rated versions)
- A Appendix A: Technical reference
- B Appendix B: HART communications
- C Appendix C: Certificates and support
- 13 List of abbreviations
- 14 LCD menu structure
- Glossary
- Index
Parameter reference
SITRANS LR250 (HART)
Operating Instructions, 01/2014, A5E32220602-AB
137
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 221)
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
TVT Hover Level
④
echo marker
②
default TVT
⑤
material level
③
false echo