KROHNE OPTISWITCH 3300C NAMUR EN - Manual (Page 8)

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 virtually unaffected by the chemical and physical
properties of the bulk solid.
It functions even when exposed to strong external vibration or
changing products.
Solid detection in water
If OPTISWITCH 3300 C was ordered for detection of solids in
water, the tuning fork is adjusted to the density of water. In the
air or when covered by water (density: 1 g/cm³/0.036 lbs/in)
OPTISWITCH 3300 C 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 OPTISWITCH 3300 C continuously mon-
itors 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.
OPTISWITCH 3300 C with NAMUR electronics can be
connected to different NAMUR amplifiers depending on your
requirements. The specifications for NAMUR amplifiers are
available in the "Technical data".
The exact range of the power supply is stated in the "Technical
data" in the "Supplement".
3.3 Operation
With the factory setting, products with a density of >0.02 g/cm³
(>0.0008 lbs/in³) can be measured. The instrument can also
be adapted to products with lower density >0.008 g/cm³
(>0.0003 lbs/in³).
Physical principle
Power supply
8 OPTISWITCH 3300 C - with NAMUR output
Product description
31358
-EN
-060830