8
3 Product description
OPTISWITCH 3300 C • Transistor (NPN/PNP)
29962-EN-210706
3.2 Principle of operation
OPTISWITCH 3300 C is a point level sensor with tuning fork for point
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, OPTISWITCH 3300 C is virtu-
ally 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 OPTISWITCH 3300 C 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), OPTISWITCH 3300 C signals
"uncovered". Only when the vibrating element is also covered with
solids (e.g. sand, sludge, gravel etc.) will the sensor signal "covered".
Function monitoring
The electronics module of OPTISWITCH 3300 C continuously moni-
tors the following criteria:
•
Correct vibrating frequency
•
Line break to the piezo drive
If a malfunction is detected or in case of voltage supply, the electron-
ics takes on a defined switching status, i.e. the output is open (safe
state).
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.
OPTISWITCH 3300 C is a compact instrument, i.e. it can be oper-
ated 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 Adjustment
On the electronics module you will find the following display and
adjustment elements:
•
Signal lamp for indication of the switching condition (green/red)
•
Potentiometer for adaptation to the product density
•
Mode switch for selecting the switching condition (min./max.)
Application area
Functional principle
Voltage supply
