Siemens Sitrans LR250 Instruction Manual page 5

Appendix C: Maintenance ...........................................................................................102
Unit Repair and Excluded Liability ................................................................................................102
Appendix D: Technical Reference .............................................................................103
Principles of Operation ....................................................................................................................103
Echo Processing ...............................................................................................................................103
Process Intelligence ...............................................................................................................103
Time Varying Threshold (TVT) Curves ...............................................................................104
Echo Lock ..................................................................................................................................104
Echo Position Detection ........................................................................................................105
Auto False Echo Suppression ..............................................................................................105
Measurement Range .......................................................................................................................106
Near Range ..............................................................................................................................106
Far Range ..................................................................................................................................106
Measurement Response .................................................................................................................106
mA Output ...........................................................................................................................................107
Damping ..............................................................................................................................................107
Loss of Echo (LOE) ............................................................................................................................108
Fail-safe Mode ...................................................................................................................................108
Fail-safe Timer .........................................................................................................................108
Fail-safe value ..........................................................................................................................108
Maximum Process Temperature Chart .......................................................................................109
Process Pressure/Temperature derating curves .....................................................................110
Horn Antenna or Wave Guide ..............................................................................................111
Loop power .........................................................................................................................................114
Typical Connection Drawing ................................................................................................114
Allowable operating area of SITRANS LR250 ..................................................................114
Startup Behavior .....................................................................................................................115
Appendix E: Application Examples ............................................................................116
Liquid resin in storage vessel, level measurement ........................................................116
Horizontal vessel with volume measurement ..................................................................118
Application with Stillpipe .......................................................................................................120
Appendix F: HART Communications .........................................................................122
SIMATIC PDM ...................................................................................................................................122
HART Device Description (DD) ......................................................................................................122
HART Communicator 375 Menu Structure .................................................................................123
Supported HART Commands .........................................................................................................126
Universal and Common Practice Commands ..................................................................126
Device Specific Commands ..................................................................................................126
Appendix G: Software Revision History ....................................................................127
Glossary ..........................................................................................................................129
Index ................................................................................................................................133
LCD menu structure ......................................................................................................137
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