VEGA VEGAPULS 45 4 … 20 mA; HART compact sensor - Manual (Page 11)

VEGAPULS 42, 44 and 45 – 4 … 20 mA 11
VEGAPULS 44
Pipe antenna
consisting of horn
antenna and
bypass tube
VEGAPULS 42
Pipe antenna
consisting of horn
antenna and
bypass tube Pipe antennas
Pipe antennas consisting of horn antenna
and standpipe or bypass tube
Only in conjunction with a
measuring tube, i.e. with a
surge or bypass tube (which
can also be curved), do horn
antennas form a complete
antenna system. The meas-
uring tube acts as a conduc-
tor for the radar signals. The
running time of the radar
signals changes in the tube
and depends on the tube
diameter. Therefore, the
sensor must be informed
about the tube inner diam-
eter so that the change in the
running time can be taken
into account and accurate
level signals outputted. Pipe
antennas are especially
suitable for very agitated
products or for products
with very small dielectric
constant.
The antennas are character-
ised by a very high antenna
gain. High reliability can be
achieved even with products
having poor reflective prop-
erties.
Pipe antenna integrated in the sensor
VEGAPULS series 45 was a further develop-
ment of the concept of VEGAPULS 42 and 44
sensors being used in conjunction with surge
or bypass tubes. This sensor was designed
with an optimised measuring tube up to 4 m
long which enables high-precision level
measurement also of products with very
small dielectric constants
ε
r
= 1.4 … 1.8 (e.g.
liquid gas).
VEGAPULS 45
with thread,
pipe antenna
integrated in the
sensor
VEGAPULS 45
with flange,
pipe antenna
integrated in the
sensor
Types and versions