Appendix D: Technical Reference; Principles Of Operation; Echo Processing; Process Intelligence - Siemens sitrans LR200 Instruction Manual

Appendix D: Technical Reference

Principles of Operation

SITRANS LR200 is a sophisticated radar instrument that uses advanced microwave pulse
1)
technology to provide non-contacting continuous level measurement in liquids or
slurries. Radar level measurement uses the time of flight principle to determine distance
to a material surface. The device transmits a signal and waits for the return echo. The
transit time is directly proportional to the distance from the material.
Pulse radar uses polarized electromagnetic waves. Microwave pulses are emitted from
the antenna at a fixed repetition rate, and reflect off the interface between two materials
with different dielectric constants (the atmosphere and the material being monitored).
Electromagnetic wave propagation is virtually unaffected by temperature or pressure
changes, or by changes in the vapor levels inside a vessel. Electromagnetic waves are
not attenuated by dust.
SITRANS LR200 consists of an enclosed electronic circuit coupled to an antenna and
process connection. The electronic component generates a radar signal (6.3 GHz in North
America, 5.8 GHz elsewhere) that is directed to the antenna.
The signal is emitted from the antenna, and the reflected echoes are digitally converted
to an echo profile. The profile is analyzed to determine the distance from the material
surface to the sensor reference point
material level.

Echo Processing

Process Intelligence

The signal processing technology embedded in Siemens radar level devices is known as
Process Intelligence.
Process intelligence provides high measurement reliability regardless of the dynamically
changing conditions within the vessel being monitored. The embedded Process
Intelligence dynamically adjusts to the constantly changing material surfaces within
these vessels.
1)
The microwave output level is significantly less than that emitted from cellular
phones.
2)
Dimensions: Uni-construction Polypropylene Rod Antenna
See
figuration, and
Page 104 SITRANS LR200 (PROFIBUS PA)– INSTRUCTION MANUAL
2)
. This distance is used as a basis for the display of
Appendix H: Flange Adapter Versions
on page 10 for the standard con-
on page 142 for other configurations.
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