KROHNE OPTISWITCH 3300 C Handbook page 12

4 Mounting
Inflowing medium
Lock fitting
Nozzle
Material cone
12
not use an overly long extension tube for OPTISWITCH 3300 C, but
check if you can mount a short level switch on the side of the vessel in
horizontal position.
Extreme vibration caused by the process or the equipment, e.g. agita-
tors or turbulence in the vessel, e.g. by fluidisation, can cause the
extension tube of OPTISWITCH 3300 C to vibrate in resonance. This
leads to increased stress on the upper weld joint. Should a longer
tube version be necessary, you can provide a suitable support directly
above the vibrating element to secure the extension tube.
This measure applies mainly to applications in Ex areas. Make sure
that the tube is not subject to bending stress due to this measure.
If OPTISWITCH 3300 C is mounted in the filling stream, unwanted
false measurement signals can be generated. For this reason, mount
OPTISWITCH 3300 C at a position in the vessel where no disturbanc-
es, e.g. from filling openings, agitators, etc., can occur.
This applies particularly to instrument types with long extension tube.
Fig. 3: Inflowing medium
OPTISWITCH 3300 C can be mounted with a lock fitting for height
adjustment. Take note of the pressure information of the lock fitting.
The vibrating element should protrude into the vessel to avoid
buildup. For that reason, avoid using mounting bosses for flanges
and screwed fittings. This applies particularly to use with adhesive
products.
In silos for bulk solids, material cones can form and change the
switching point. Please keep this in mind when installing the sensor
in the vessel. We recommend selecting an installation location where
the vibrating fork detects an average value of the material cone.
OPTISWITCH 3300 C • Transistor (NPN/PNP)