User Manual

12 VEGAPULS 42 and 44 – 4 … 20 mA
1.4 Antennas
The antenna is the eye of the radar sensor.
An uninitiated observer would probably not
realise how carefully the antenna geometry
must be adapted to the physical properties
of electromagnetic fields.
The geometrical form determines focal prop-
erties and sensitivity - the same way it deter-
mines the sensitivity of a unidirectional
microphone.
Four antenna systems are available for differ-
ent applications and process requirements.
Horn antennas
Horn antennas focus the
radar signals very well.
Manufactured of 1.4435
(stainless steel) or Hastel-
loy C22, they are very rug-
ged, and are physically as
well as chemically, resistant.
They are suitable for pres-
sures up to 40 bar and for
product temperatures up to
150°C. The horn diameters
determine the focussing of
the radar signals. The an-
tenna gain grows stronger
with increasing diameter
(40, 48, 75, 95 mm). The
antenna gain represents
the ratio of emitted energy
to received echo energy.
Product description
2
2
4 ...20 mA
HART
®
handheld on the 4 … 20 mA signal cable
For adjustment, just connect the HART
®
hand-
held to the 4 … 20 mA output signal cable or
insert the two communication cables of the
HART
®
handheld into the adjustment jacks on
the sensor.
VEGAPULS 42
VEGAPULS 44