Siemens sitrans LR 400 Instruction Manual page 82

dielectric constant is directly proportional to an increase in signal amplitude. The value is
usually given relative to a vacuum /dry air: the dielectric constant of air is 1¹.
DSP: Digital signal processor
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: the recognition of the validity of the echo. A measure of echo reliability.
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 Processing: the process by which the radar unit determines echoes.
Echo Strength: describes the strength of the selected echo in dB above 1 µV rms.
Echo Profile: a graphical display of a processed echo.
false echo: any echo which is not the echo from the desired target. Generally, false echoes are
created by vessel obstructions.
fixed target: permanently installed objects inside the vessel which may cause reflective
interference, e.g. struts, agitators, feed pipes, etc.
FMCW: Frequency Modulated Continuous Wave method
frequency: the number of periods occurring per unit time. Frequency may be stated in cycles
per second.
frequency deviation: changing the transmission frequency in the FMCW method
hertz (Hz): unit of frequency, one cycle per second. 1 Gigahertz (GHz) is equal to 10
horn antenna: a conical, horn-shaped antenna which focuses microwave signals. The larger
the horn diameter, the more focused the radar beam.
LRV: Lower limit of the valid measuring range as a distance from the bottom inside of the
vessel.
material or measuring medium: the contents of the vessel
microwaves: the term for the electromagnetic frequencies occupying the portion of the radio
frequency spectrum from 1 GHz to 300 GHz.
multiple echoes: secondary echoes that appear as double, triple, or quadruple echoes in the
distance from the target echo.
nozzle: a length of pipe mounted onto a vessel that supports the flange.
nozzle height: distance from the top of the inside of the vessel to the bottom of the device
flange.
parameters: in programming, variables that are given constant values for specific purposes or
processes.
7ML19985JC02 SITRANS LR 400 (Solids) – INSTRUCTION MANUAL
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