VEGA VEGAPULS 43 Profibus PA - Manual (Page 4)

4 VEGAPULS 43 – Profibus PA
Product description
1 Product description
Sensors used in the food and pharmaceutical
industries must meet very high demands:
they must have long-term stability, they must
be accurate, robust, easy to set up, chemi-
cally resistant and flawlessly hygienic. Many
level sensors meet those demands only
halfway. Radar sensors, which are otherwise
widely used, are not usually found in hygienic
and sterile applications because their anten-
nas are difficult to clean. The newly devel-
oped VEGAPULS 43 radar sensor was de-
signed especially for areas of application in
hygienic and sterile production. Radar sen-
sors are ideal because they operate without
touching the medium, are free of wear and
ageing, and perform well regardless of pres-
sure (-1 … +40 bar) or temperature
(-40°C … +150°C). The new antenna design
of VEGAPULS 43, having no recesses or
gaps, presents a smooth surface (like a
smooth vessel wall) to CIP and SIP proc-
esses. It allows all the methods of modern,
environment-friendly system hygiene and
has of course EHEDG, FDA and 3A approv-
als. The sensor faces the medium only with a
small, extremely dense TFM-PTFE surface
through which it transmits very small
(0.15 mW) radar pulses. A very fast, intelli-
gent electronics creates from the resulting
echoes a precise image of the surroundings
and calculates from the pulse running time
the level in the vessel every 0.1 s. This value
is then outputted as a 4 … 20 mA signal.
Compared with the PTFE commonly used in
hygienic applications, the improved TFM-
PTFE has a far denser polymer structure and
a noticeably higher surface quality (Ra < 0.8).
As a result, proven radar technology is now
available for sterile production processes.
The spectrum of applications for the new
radar sensor is broad and varied: serum
production, face cream, fruit juice, etc.
Due to their small housing dimensions and process fittings, the compact sensors are
unobstrusive and, above all, cost-effective
monitors of your product levels. With their
integrated display, they enable high-
precision level measurements and can be
used for applications in which the
advantages of non-contact measurement
could never before be realized.
VEGAPULS radar sensors are perfectly
adapted to two-wire technology. The supply
voltage and the output signal are transmitted
via one two-wire cable. The instruments
produce an analogue 4 … 20 mA signal as
output, i.e. measurement signal.
1.1 Function
Ra dio d etecting a nd r anging: Radar.
VEGAPULS radar sensors are used for non-
contact, continuous distance measurement.
The measured distance corresponds to a
filling height and is outputted as level.
Measuring principle:
emission – reflection – reception
Extremely small 26 GHz radar signals are
emitted from the antenna of the radar sensor
as short pulses. The radar pulses reflected
by the sensor environment and the product
are received by the antenna as radar ech-
oes. The running period of the radar pulses
from emission to reception is proportional to
the distance and hence to the level.