VEGA VEGAVIB 61 - transistor (NPN-PNP) - Manual (Page 8)

3 .2 Principle of operation
VEGAVIB 61 is a point level sensor with vibrating rod for level
detection.
It is designed for industrial use in all areas of process technology and
is preferably used for bulk solids.
Typical applications are overfill and dry run protection. Thanks to its
simple and robust measuring system, VEGAVIB 61 is virtually
unaffected by the chemical and physical properties of the bulk solid.
It also works when subjected to strong external vibrations or changing
products.
Solid detection in water
If VEGAVIB 61 was ordered for solid detection in water, the vibrating
rod is calibrated to the density of water. If covered by water (density:
1 g/cm³/0.036 lbs/in) VEGAVIB 61 signals "uncovered". Only if the
vibrating element is also covered with solids (e.g. sand, sludge, gravel
etc.) will the sensor signal "covered".
Fault monitoring
The electronics module of VEGAVIB 61 monitors continuously the
following criteria:
l Correct vibrating frequency
l Line break to the piezo drive
If a malfunction is detected or in case of power failure, the electronics
takes on a defined switching condition, i.e. the output is open (safe
condition).
The vibrating rod is piezoelectrically energised and vibrates at its
mechanical resonance frequency of approx. 360 Hz. When the
vibrating rod is submerged in the product, the vibration amplitude
changes. This change is detected by the integrated electronics module
and converted into a switching command.
VEGAVIB 61 is a compact instrument, i.e. it can be operated without
external evaluation system. The integrated electronics evaluates the
level signal and outputs a switching signal. With this switching signal, a
connected device can be operated directly (e.g. a warning system, a
pump etc.).
The data for power supply are specified in chapter "Technical data".
3 .3 Operation
With the factory setting, products with a density of > 0.05 g/cm³
(0.002 lbs/in³) can be measured. It is possible to adapt the instrument
for products with lower density > 0.02 g/cm³ (0.0007 lbs/in³).
On the electronics module you will find the following indicating and
adjustment elements:
Application area
Functional principle
Voltage supply
8 VEGAVIB 61 • - transistor (NPN/PNP)
3 Product description
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-EN
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