VEGA VEGASWING 83A EXD - Manual (Page 3)

VEGASWING 81A EXD and 83A EXD 3
Product description
1 Product description
1.1 Function and configuration
VEGASWING series 80 A vibrating level
switches detect levels of liquids with a vis-
cosity of 0,2 mPa s up to 10.000 mPa s and a
density ³ 0,5 g/cm
3 . Their modular configura-
tion allows the use in vessels, tanks and
pipelines. Typical applications are overfill and
dry run protections.
Due to the simple and rugged measuring
system, VEGASWING can be used virtually
in any liquid independent of the chemical and
physical characteristics. It works also under
arduous conditions such as turbulences, air
bubbles, foam generation or varying meas-
ured product and is insensitive to external
vibrations.
With the mechanical connection thread,
conus, bolting and flange, the versions are
also suitable for level detection of liquids in
the food pr ocessing industr y. For these ap-
plications the tuning fork and the extension
tube are polished.
For the use in very aggressive products,
Hastelloy C4 and coatings ECTFE (Halar)
and enamel are used for VEGASWING 81 A
and 83 A.
VEGASWING 83A with flange can be coated
with enamel up to 1200 mm and ECTFE (Ha-
lar) up to 1,6 m tube length.
For product temperatures of more than
100°C up to 150°C, VEGASWING 81 A and
83 A can be equipped with a temperature
adapter.
Function
The tuning fork is piezoelectrically energised
and vibrates at a resonance frequency of
approx. 400 Hz. If the tuning fork is covered
by the product, the resonance frequency
changes. This frequency change is detected
by the integral oscillator and converted into a
switching command. With a mode switch the
switching condition can be determined (over -
fill or dry run protection).
The oscillator of VEGASWING monitors con-
tinuously the instrument. The following criteria
are checked:
- corrosion or damage of the tuning fork
- vibration failure
- line break to the piezo actuation
- too low vibrating frequency
- corrosive medium penetrated into the sen-
sor from the vessel side.
With a connected signal conditioning instru-
ment (oscillator SWING E82 Z) in addition
more functions can be monitored. With oscil-
lator SWING E82 Z and appropriate signal
conditioning instrument, the function of the
complete measuring chain can be monitored
by key pressing. This is valid according to
the general type approval acc. to WHG as
recurring test. More information with the ap-
propriate signal conditioning instrument.
If one of the stated failures is determined or in
case of voltage loss, the electronics takes a
defined switching condition, i.e. dependent
on the electronics version
- the non-contact switch opens
- the relay deenergizes
- the output transistor blocks.
- a fault signal is triggered.
With the two-wire output version, the failure is
signalled via a defined current to the con-
nected VEGATOR signal conditioning instru-
ment.