VEGA VEGAWAVE 61 - contactless electronic switch - Manual (Page 8)

3 .2 Principle of operation
VEGAWAVE 61 is a point level sensor with tuning fork 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, VEGAWAVE 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 VEGAWAVE 61 was ordered for solids detection in water, the tuning
fork is set to the density of water. In air or when immersed in water
(density: 1 g/cm³/0.036 lbs/in), VEGAWAVE 61 signals "uncovered".
Only when 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 VEGAWAVE 61 monitors continuously the
following criteria:
l Correct vibrating frequency
l Line break to the piezo drive
If one of the stated malfunctions is detected or in case of power failure,
the electronics takes on a defined switching condition, i.e. the
contactless electronic switch opens (safe condition).
The tuning fork is piezoelectrically energised and vibrates at its
mechanical resonance frequency of approx. 150 Hz. When the tuning
fork is submerged in the product, the vibration amplitude changes.
This change is detected by the integrated electronics module and
converted into a switching command.
VEGAWAVE 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 > 0.02 g/cm³
(0.0008 lbs/in³) can be measured. The instrument can also be adapted
to products with lower density > 0.008 g/cm³ (0.0003 lbs/in³).
On the electronics module you will find the following indicating and
adjustment elements:
Application area
Functional principle
Voltage supply
8 VEGAWAVE 61 • - contactless electronic switch
3 Product description
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