KROHNE OPTISWITCH 3100C Transistor EN - Manual (Page 8)

It functions even when exposed to strong external vibration or
changing products.
Solid detection in water
If OPTISWITCH 3100 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 3100 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 3100 C continuously mon-
itors the following criteria:
l
Correct vibrating frequency
l
Line break to the piezo drive
If one of the stated malfunction is detected or in case of power
failure, the electronics takes on a defined switching condition,
i.e. the output transistor blocks (safe condition).
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 3100 C is a compact instrument, i.e. it can be
operated 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
directly activated (e.g. a warning system, a PLC, a pump etc.).
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).
On the electronics module you will find the following indicating
and adjustment elements:
l signal lamp for indication of the switching condition (green/
red)
l
potentiometer for adaptation to the product density
Physical principle
Power supply
8 OPTISWITCH 3100 C - with transistor output
Product description
29954
-EN
-060830