Siemens Sitrans LR250, Руководство по эксплуатации, Страница: 295 / 306

Glossary
SITRANS LR250 (PROFIBUS PA)
Operating Instructions, 08/2014, A5E32221386-AC
293
dielectric constant (dK)
the ability of a dielectric to store electrical potential energy under the influence of an electric field.
Also known as Relative Permittivity. An increase in the
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 1.
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.