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)
134 Operating Instructions, 01/2014, A5E32220602-AB
CLEF Range (2.8.4.4.)
Note
CLEF Range is referenced from Far range.
The CLEF algorithm is used mainly to allow correct level reporting for low dK materials which
may otherwise cause an incorrect reading in an empty or almost empty vessel.
It is used from Low Calibration Point (process empty level ) up to the level defined by CLEF
Range (see illustration below). Above that point the Center algorithm is used. For more detail
see CLEF Range (Page 220).
Values
Range: 0 to 20 m (0 to 65.6 ft)
Default: 0.0 m
Related parameters
Position Detect (2.8.4.2.)
①
CLEF Range
②
Sensor reference point
③
Low Calibration Point (process empty level )
In applications with low dK materials we recommend setting CLEF Range to 0.5 m (1.64 ft) and
Position Detect (2.8.4.2.)
to Hybrid.
Sampling (2.8.5.)
Provides a method of checking the reliability of a new echo before accepting it as the valid
reading, based on numbers of samples above or below the currently selected echo.