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
Appendix A: Technical reference
A.2 Echo Processing
SITRANS LR250 (HART)
Operating Instructions, 01/2014, A5E32220602-AB
223
A.2.7
Measurement Range
Near Range (2.8.1.)
Near Range programs SITRANS LR250 to ignore the zone in front of the antenna. The default
blanking distance is 50 mm (1.97") from the end of the antenna.
Near Range allows you to increase the blanking value from its factory default. But
Auto False
Echo Suppression (2.8.7.1.)
is generally recommended in preference to extending the blanking
distance from factory values.
Far Range (2.8.2.)
Far Range can be used in applications where the base of the vessel is conical or parabolic. A
reliable echo may be available below the vessel empty distance, due to an indirect reflection
path.
Increasing Far Range to 30% or 40% can provide stable empty vessel readings.
A.2.8
Measurement Response
Note
U
nits are defined in
Units (2.2.1.)
and are in meters by default.
Response Rate (2.4.1.)
limits the maximum rate at which the display and output respond to
changes in the measurement. There are three preset options: slow, medium, and fast.
Once the real process fill/empty rate (m/s by default) is established, a response rate can be
selected that is slightly higher than the application rate. Response Rate automatically adjusts the
filters that affect the output response rate.
Response Rate (2.4.1.)
Fill Rate per Minute (2.4.2.)/Empty Rate per
Minute (2.4.3.)
Damping Filter (2.2.4.)
*
Slow
0.1 m/min (0.32 ft/min)
10 s
Medium
1.0 m/min (3.28 ft.min)
10 s
Fast
10.0 m/min (32.8 ft/min)
0 s