VEGA VEGASWING 83A - Manual (Page 4)

4 VEGASWING 81A and 83A
Product description
1 Product description
1.1 Function and configuration
VEGASWING series 80 A vibrating level
switches detect the levels of liquids with a
viscosity between 0,2 mPa s and
10.000 mPa s and densities ³ 0,5 g/cm
3 .
Their modular design allows them to be used
in vessels, tanks and pipelines. T ypical appli-
cations involve overfill and dry run protection.
Thanks to its simple and rugged measuring
system, VEGASWING can be used in almost
any liquid regardless of its chemical and
physical properties. It also works well under
difficultconditions such as turbulence, air
pockets, foam formation, or changes in mate-
rial, and is insensitive to external vibrations.
VEGASWING with their mechanical connec-
tion thread, cone, bolting and flange are also
suitable for level detection of liquids in the
food pr ocessing industr y. The tuning fork
and the extension tube are polished for such
applications.
For the use in very aggressive products,
Hastelloy C4 and coatings ECTFE (Halar)
and enamel are used for VEGASWING 81 A
and 83 A.
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. The resonance frequency
changes when the tuning fork is covered by
the material. This frequency change is de-
tected by the integral oscillator and con-
verted into a switching command.The
switching condition (overfill or dry run protec-
tion) can be selected using the mode switch.
The oscillator of VEGASWING continuously
monitors the instrument for the following
faults:
- tuning fork corrosion or damage,
- absence of vibration,
- piezo drive cable malfunction,
- vibrating frequency too low ,
- corrosive medium penetrating the sensor
from the vessel.
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
at the touch of a button. This is valid accord-
ing to the general type approval acc. to WHG
as recurring test. More information is pro-
vided with the particular signal conditioning
instrument.
Should one of the above-mentioned faults
occur, or the power supply fails, the electr on-
ics react by switching to a defined switching
state, i.e. dependent on the electr onics ver-
sion
- opening the non-contact switch,
- de-energising the r elay, o r
- blocking the output transistor .
With the two-wire output version, the failure is
signalled via a defined current to the con-
nected VEGATOR signal conditioning instru-
ment.