Level limit switch
Series VN 1000 / 2000 / 5000 / 6000
Technical information / Instruction manual
page
Electronic module
8/16 mA or 4-20 mA
The output can either be set to give
8/16 mA or to give 4-20 mA. On setting
4-20 mA the output depends on the
amplitude of the vibration of the fork.
Characteristic setting
If the sensor is used to indicate full
load, set to Falling Characteristic.
Power failure or line break is regarded
as „full“ signal (protection against
overcharging).
If the sensor is used to indicate empty
load, set to Rising Characteristic.
Power failure or line break is regarded
as „empty“ signal (protection against
running dry).
Weak vibration diagnosis
The quality of the measurement is related to the vibration amplitude of the sensor and can be
evaluated by the output current and by the internal LED „Diagnosis“ as follows:
•
Safe measurement (clean fork):
The vibration amplitude is strong. There is enough safety to the switching point.
•
Weak vibration amplitude:
A fork with so much material build up, that a weak vibration amplitude is indicated.
The sensor is still working, but it can happen, that gradually the amplitude decreases further (maybe
by increasing material build up) and the measurement fails. If low vibration amplitude is indicated, the
sensitivity setting should be changed from „High sensitivity“ to „Low sensitivity“, if material density
is not too low, and the fork should be cleaned from material. Remark: By shifting the setting to „Low
sensitivity“, the internal amplification of the vibration signal in the electronic is increased. This allows
more build up of material.
•
Fork fully covered:
The sensor is fully covered with material. The vibration has stopped.
“TEST” Button
If the sensor is not covered with material:
By pressing this button, the vibration will stop and the signal output will switch to indicate “covered
sensor”. This allows to test the vibration and the electronic for function without removing the sensor
from the silo.
Remark: By pressing the button, the internal signal from the piezo-element, that indicates the vibration
of the fork, is shortened. The electronic misses the vibration signal and indicates “covered sensor”.
If the sensor is covered with material:
Pressing of this button has no effect.
Factory provided settings
• D OFF
• 8/16 mA
•
• High sensitivity
“TEST”Button
Electronic module
LED „Diagnosis“
Low
sensitivity
LED „Signal output“
Settings
High
sensitivity
Low sensitivity High sensitivity
VN 1000/ 5000
150 g/l (9 lb/ft
3
) 50 g/l (3 lb/ft
3
)
VN 2000/ 6000
75 g/l (4,5 lb/ft
3
) 20 g/l (1.2 lb/ft
3
)
VN 2000/ 6000
with enhanced sensitivity
20 g/l (1.2 lb/ft
3
) 5 g/l (0.3 lb/ft
3
)
Signal output and Diagnosis
Vibranivo
®
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9
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VN 1000 / 2000 / 5000 / 6000 g
gi180713
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