KROHNE OPTISWITCH 3100C 2wire 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 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.
Depending on your requirements, OPTISWITCH 3100 C with
two-wire electronics can be connected to different signal
conditioning instruments. Compatible signal conditioning in-
struments are listed under "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).
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
l
mode switch for selection of the output current
Physical principle
Power supply
8 OPTISWITCH 3100 C - with two-wire output
Product description
29955
-EN
-060830