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
Glossary
SITRANS LR250 (HART)
Operating Instructions, 01/2014, A5E32220602-AB
255
echo
a signal that has been reflected with sufficient magnitude and delay to be perceived in some
manner as a signal distinct from that directly transmitted. Echoes are frequently measured in
decibels relative to the directly transmitted signal.
Echo Confidence
describes the quality of an echo. Higher values represent higher quality. Echo Threshold defines
the minimum value required for an echo to be accepted as valid and evaluated.
Echo Lock Window
a window centered on an echo in order to locate and display the echo’s position and true
reading. Echoes outside the window are not immediately processed.
Echo Marker
a marker that points to the processed echo.
Echo Processing
the process by which the radar unit determines echoes.
Echo Profile
a graphical display of a processed echo.
Echo Strength
describes the strength of the selected echo in dB referred to 1 μV rms.
false Echo
any echo which is not the echo from the desired target. Generally, false echoes are created by
vessel obstructions.
frequency
the number of periods occurring per unit time. Frequency may be stated in cycles per second.