User's Manual

7ML19985FH04 SITRANS LR 400 – INSTRUCTION MANUAL Page 79
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Glossary
Glossary
Term Explanation
Antenna offset
Propagation time of the signal in the sensor, expressed as a dis-
tance
Current limit
The maximum possible value of the output signal in fault-free
operation in mA. The value of the fail signal may be above the
current limit with 24 mA.
Customer code
User-defined code which protects the device against accidental
programming.
Dead band Value range below the device flange declared unmeasurable.
Echo movement
Sensor parameter for a fuzzy rule which takes into account
dynamic procedures in the measuring medium, for example, and
therefore rules out fixed targets.
Fixed target
Permanently installed objects inside the vessel which may cause
reflective interference, e.g. struts, agitators, feed pipes etc.
FMCW method F
requency Modulated Continuous Wave method
Frequency deviation Changing the transmission frequency in the FMCW method.
Level Distance from the LRV to the surface of the measuring medium.
LRV
Lower limit of the valid measuring range as a distance from the
bottom inside of the vessel.
Measuring medium The (solid or liquid) contents of the vessel.
Multiple echo
evaluation
Sensor parameter for a fuzzy rule which detects and suppresses
multiple reflections of the measuring signal at the vessel walls.
Nozzle height
Distance from the top of the inside of the vessel to the bottom of
the device flange.
PELV P
rotected Extra Low Voltage
PTFE Polytetrafluorethylene
SELV S
afety Extra Low Voltage
Signal-to-noise ratio
Measure of the strength of reflection of the measuring medium
in the current measuring situation in dB.
vessel height Distance between the floor and top of the vessel.
Triple reflector Metal instrument formed as a cubic segment with right angles.
URV
Upper limit of the valid measuring range as a distance from the
bottom inside of the vessel.
Validity Measure of the certainty of the current measured value in %.