Siemens SITRANS LUT400 Operating Instructions Manual page 324

frequency
the number of periods occurring per unit time. Frequency may be stated in cycles per
second.
HART
Highway Addressable Remote Transducer. An open communication protocol used to
address field devices.
Hertz (Hz)
unit of frequency, one cycle per second. 1 Gigahertz (GHz) is equal to 10
multiple echoes
secondary echoes that appear as double, triple, or quadruple echoes in the distance from
the target echo.
parameters
in programming, variables that are given constant values for specific purposes or processes.
range
distance between a transducer and a target.
shot
one transmit pulse or measurement.
speed of sound
the speed at which sound is propagated through some medium under specified conditions.
stilling well
see stillpipe.
stillpipe
a pipe that is mounted inside a vessel parallel to the vessel wall, and is open to the vessel at
the bottom.
TVT (time varying threshold)
a time-varying curve that determines the threshold level above which echoes are determined
to be valid.
322
Hz.
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Operating Instructions, 07/2019, A5E33329501-AC
SITRANS LUT400