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Vibrating Fork Level Switch
FILPRO
Working Principle:
The vibra ng fork type level sensor works on the principle of tuning forks. There is a stack of piezo ceramic crystals
located inside the fork assembly. The stack is so selected that on applica on of voltage, the crystals oscillate at the
natural frequency of the fork assembly. This frequency is con nuously monitored by the internal electronic
circuitry. When the fork comes in contact with liquids, the frequency slightly changes, and this change is sensed by
the electronics which in turn send out a signal. This signal is processed to give out a transistor output or relay
output etc as the case may be.
Key Advantages:
This assembly is immune to the type of applica on which could have foam, variable flow, bubbles, contamina on,
liquid proper es, presence of solids etc in the sensing liquid. It does not need any frequent calibra on or
adjustments and once installed and commissioned, it is free to operate for-ever.
Since the forks are under constant vibra on, the probability of any s cky material or floa ng solvents s cking to it
is minimal. Also, it is free from influences of temperatures and pressures.
Applications:
The vibra ng fork sensor can be used for virtually every type of liquid level measurement applica on where
point level is of importance.
This could be for overfill level, low or high level, pump protec on from dry run, applica ons which require high
levels of hygiene, RF based wireless applica ons etc. Since the fork is made from SS 316 L, it is free from corrosion
or aging, and can even be used in food industries etc.
Mounting:
For best results, it is recommended that correct installa on prac ce is followed.
1. The fork fingers should not be directly under the discharge loca on of liquids into the tank.
2. If used for solid medium, a protec ng canopy above the fingers is recommended.
3. The face plates of the fingers should be ver cal in side mount applica ons. See figure a ached for further
clarity.
4. It is allowed to mount the assembly slightly lted to the horizontal, this will help in preven ng material build up.
5. While moun ng from top of the tank, axis orienta on of face plates of the fork does not ma er.
6. The complete fork should protrude into the tank, and not part of it, and there should be no side cavity.
The purpose is to avoid material build up inside cavi es.
FILPRO
General specifications:
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Description
24 V DC
90 mA Max
PNP transistor
Fixed 5 seconds
Screw terminals, 1.5 sq mm
PG 16 provision two numbers
WP/FLP Cast Aluminium
85 deg C for electronics
1 inch BSP threaded
150 deg C
100 mm
SS 316
Item
Supply voltage
Current consumption
Output
Time delay
Electrical Connection
Cable gland
Electronics
Temperature
Process connection
Process temperature
Probe length
Wetted parts
Dimension details:
22
Electronics Enclosure
35 hex
1" BSP
15
25
100
33
93
Variable
Fixed
Installation :
Horizontal or ver cal or slight angle with respect to horizontal.
In horizontal installa ons, it is recommended to install a canopy above
the fork so that material does not discharge directly on the fingers.
Works effec vely on solids as well as liquids.
Filpro Sensors Pvt. Ltd.
No 130, 10th Cross, Petechennappa Industrial Estate, Kamakshipalya,
Magadi Main Road, Bangalore - 560 079. Phone : 080 23286463
E-mail : sales@filprosensors.com
Website : www.filprosensors.com
ISO 9001