Siemens Sitrans LR250, Руководство по эксплуатации, Страница: 296 / 306

Glossary
SITRANS LR250 (PROFIBUS PA)
294
Operating Instructions, 08/2014, A5E32221386-AC
frequency
the number of periods occurring per unit time. Frequency may be stated in cycles per second.
hertz (Hz):
unit of frequency, one cycle per second. 1 Gigahertz (GHz) is equal to 10
9
Hz.
horn antenna
a conical, horn-shaped antenna which focuses microwave signals. The larger the horn diameter,
the more focused the radar beam.
inductance
the property of an electric circuit by virtue of which a varying current induces an electromotive
force in that circuit or in a neighboring circuit. The unit is a Henry.
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.
Near Blanking
see Blanking.
nozzle
a length of pipe mounted onto a vessel that supports the flange.
parameters
in programming, variables that are given constant values for specific purposes or processes.
polarization
the property of a radiated electromagnetic wave describing the time-varying direction and
amplitude of the electric field vector.