The SLC... series level limit switch can be used
for level limit detection of solids that are
fine/coarse or in bulk. This capacitance based
level measurement switch can also be used for
liquid level measurement including water. This
small level switch cab also be used with liquids
that are sticky/non-sticky corrosive or
non-corrosive for switching conveyors off,
indicating empty tank condition, preventing
pumps for running dry and for detecting the
separation layers accurately.
The SLC... series capacitance based level switch
has been used by many of our clients
successfully in the Cement, Plastic, Power,
Food, Chemicals, Fertilizer, Sugar, Detergent
and many other industries
The SLC... series consists of an evaluation
unit, an electronic insert and the probe. The
probe can be mounted form the top or side of the
vessel. The probe system comprises a sense
electrode which is insulated from the metallic
tank by means of a suitable insulator. The sense
electrode and the vessel wall serve as the two
electrodes of a capacitor with the service
material as the dielectric. A change in material
level causes a change in the dielectric, which
in turn causes the value of this tank capacitor
to change.
An accurate measurement of this change causes an
indirect measure of level of the material in the
tank. The electronic insert measures the change
of capacitance accurately by using Radio
Frequency (R.F.) technique. The change is
converted to a DC voltage variation, which is
transmitted to the evaluation unit via a 3-core
unscreened cable for further processing. The
processed signal is used to energize or
de-energize a relay whose output contacts are
available for annunciation or control.
Salient Features
You can calibrate the level
limit evaluation unit far away from the probe.
This level switch uses ordinary 3 core cable for
interconnecting the electronic insert with the
evaluation unit. A variety of built in
multi-point evaluation units is available to
reduce the number of discrete controllers
thereby reducing the overall cost. The fail-safe
high/low selection feature is available as a
standard. This systems is economical to install
and you can even have it in circular enclosures
for your specific requirements.
Technical
Data
Evaluation Unit
Housing
: Cast Aluminium,
Weather proof,
back panel/wall
mounting
Cable Entry
: 3 Nos. / 2
Nos.
Max. Amb.
Temp.
: -20o
C to + 60o
C.
Power
Consumption
: 5 VA approx.
Mains Voltage
: 230 V or 110 V
AC (-15% to
+10%), 50 Hz; 24
V AC/DC;
90 to 260 V AC
universal power
supply. (to be
specified while
ordering).
Relay Output
: One/two set
(s) of potential
free c/o
contacts rated
at 230V AC 6A,
50 Hz for
non-inductive
load
per set
point.
Fail-Safe
Mode
: Max. or Min.
Field
selectable.
Indication
: Red LED for
alarm, Green LED
for normal,
Yellow LED for
system fault.
Response Time
: 0.2 Second
Switching
Delay for
: Adjustable
from 0.5 to 20
Second. for
probe covered or
uncovered
condition.
Connection to
Electronic
Insert
: 3 - core
unscreened
cable.
Initial
Capacitance
: 0 to 290 pf.
in 3 overlapping
ranges.
(For single
point switching)
0 to 1200 pf.
in 3 overlapping
ranges.
(For pump
control & multi
point switching)
Switching
Hysteresis
:0.5 pF.
typical. (For
independent
switching)
& Continuously
adjustable over
the entire
range. (For pump
control
switching)
Electronic
Insert - LDC 311
Housing
: Plastic,
potted in epoxy
resin.
Frequency
: 500 kHz.
(approximately).
Ambient Temp.
: -20o
C to 80o
C.
Supply
Voltage
: 15 V derived
from evaluation
unit.
Output Signal
: 3 to 12 V DC.
Probe
A wide variety
of probes with
different
mounting
connections is
available to
suit various
process
applications. We
offer specially
designed ceramic
insulated
rod/rope probes
suitable for
operating
temperatures max
up to 600o
C.
Capacitance
Level Switch (SLC... Series)
