VEGA VEGAVIB 67 - two-wire - Manual (Page 9)

Typical applications are overfill and dry run protection. Thanks
to its simple and robust measuring system, VEGAVIB 67 is
virtually unaffected by the chemical and physical properties of
the solid.
It functions even when exposed to strong external vibration or
changing products.
Solid detection in water
If VEGAVIB 67 was ordered for solid detection in water, the
tuning fork is to the density of water. In air or if covered by
water (density: 1 g/cm³/0.036 lbs/in) VEGAVIB 67 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 of VEGAVIB 67 continuously monitors the
following criteria:
l
Correct vibrating frequency
l
Line break to the piezo drive
If one of these faults is detected, the electronics signals this via
a defined current to the signal conditioning instrument. The
connection cable to the vibrating element is also monitored.
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
oscillator and converted into a switching command.
Depending on your requirements, VEGAVIB 67 with two-wire
electronics can be connected to different signal conditioning
instruments. Compatible signal conditioning instruments are
listed under "Technical data".
The exact range of the supply voltage is also specified in the
"Technical data" in the "Supplement".
3.3 Adjustment
With the factory setting, products with a density of >0.02 g/cm³
(>0.0008 lbs/in³) can be measured. It is possible to adapt the
instrument for 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:
Physical principle
Power supply
VEGAVIB 67 - with two-wire output 9
Product description
29298
-EN
-060508