6
SAFETY
PRECAUTION
(capacitance)
Step
Three
Make
a
Fail
‐
Safe
System:
Design
a
fail
‐
safe
system
that
accommodates
the
possibility
of
switch
and/or
power
failure.
OMEGA
ENGINEERING
recommends
the
use
of
redundant
backup
systems
and
alarms
in
addition
to
the
primary
system.
Adding
a
redundant
high
level
float
switch
to
the
system
is
a
cost
effective
means
to
prevent
costly
tank
overflows.
The
LVP
‐
51
‐
R
switch
has
a
single
relay.
The
normally
open
(NO)
or
normally
closed
(NC)
operation
is
user
selected
based
on
the
desired
system
control.
Always
design
a
fail
‐
safe
system
that
accommodates
for
the
possibility
of
functional
and/or
power
failure
to
the
instrument.
The
"normal"
relay
state
is
where
the
relay
coil
is
de
‐
energized
and
the
relay
indicator
is
OFF.
Therefore,
if
power
is
cut
OFF
to
the
switch
it
will
de
‐
energize
the
relay.
Make
sure
that
the
de
‐
energized
state
is
the
safe
state
in
your
system
design.
As
such,
if
switch
power
is
lost,
a
pump
will
turn
OFF
if
it
is
connected
to
the
normally
open
side
of
the
relay.
Technology:
The
non
‐
intrusive
RF
capacitance
switch
detects
the
presence
of
liquid
or
air
by
measuring
the
conductive
or
dielectric
values
which
are
present
in
all
materials.
An
electrical
capacitor
is
formed
between
the
level
switch
and
the
outer
tank
wall.
As
liquid
rises
and
falls
against
the
inner
wall,
the
capacitance
effect
is
greatly
increased
and
the
60VA
SPST
relay
changes
state.
The
sensor’s
operation
may
vary
based
on
the
dielectric
properties
of
various
application
liquids.
Liquids
with
a
dielectric
constant
less
than
20
may
not
be
detected
by
an
LVP
‐
51
‐
R
sensor.
Table
of
Common
Dielectric
Constants:
NOTE:
Liquids
with
a
conductivity
value
>
100
µS/cm
are
fine
if
coating
is
not
an
issue.
Liquids
with
a
dielectric
constant
less
than
20
will
not
be
detected
by
an
LVP
‐
51
‐
R
level
switch,
depending
on
conditions.
Acetone ..................... 21
Acetoaldehyde ....... 22.2
Acetyl methyl hexyl
ketone ........................ 28
Alcohol ........... 16 to 31
Ammonia ........ 15 to 25
Acetic acid .... 4.1 to 6.2
Butyl chloride .......... 9.6
Barium chloride 9 to 11
Benzene ................... 2.3
Benzine .................... 2.3
Barium nitrate .......... 5.6
Bromine ................... 3.1
Chlorobenzene . 4.7 to 6
Chlorotoluene .......... 4.7
Chloroform .... 4.5 to 5.0
Chlorine, liquid ....... 2.0
Carbon tetrachloride 2.2
Cyan ........................ 2.6
Cyclohexane methanol
.................................. 3.7
D.I. Water ................. 20
Ethyl toluene ........... 2.2
Ethyl alcohol ............ 23
Ethylene glycol ........ 37
Ethylene oxide .......... 14
Ethylene dichloride
.......................... 11 to 17
Ethylene chloride .. 10.5
Ethyl acetate ............ 6.4
Ethyl salicylate ........ 8.6
Ethyl stearate .......... 2.9
Ethyl silicote ........... 4.1
Formic acid .............. 59
Ferric oleate ............ 2.6
Freon ....................... 2.2
Glycerine .................. 47
Glycol ....................... 30
Glycol nitrite ............ 27
Gasoline ........... 2 to 2.2
Hydrochloric acid ... 4.6
Isobutyric acid ........ 2.7
Isobutyl methyl ketone
................................... 13
Jet fuel ..................... 1.7
Lead carbonate ......... 18
Lead nitrate ............... 38
Methyl salicylate ..... 9.0
Methanol ................... 33
Methyl alcohol . 33 to 38
Margarine, liquid
........................2.8 to 3.2
Methyl acetate ......... 7.3
N-butyl formate ....... 2.4
Nitrobenzene ... 26 to 35
Nitrotoluene ............. 25
Naphthalene .. 2.3 to 2.5
Oils, vegetable 2.5 to 3.5
Oils, mineral .. 2.3 to 2.4
Oils, petroleum
........................ 1.8 to 2.2
Oleic acid ................ 2.5
Propane, liquid
........................ 1.8 to 1.9
Potassium nitrate
........................ 5.0 to 5.9
Potassium chloride .. 5.0
Stearic acid .............. 2.3
Toluene .................... 2.4
Trichloroethylene .... 3.4
Trichloroacetic acid 4.5
Terephthalic acid
........................ 1.5 to 1.7
Thinner .................... 3.7
Urea ......................... 3.5
Vinyl chloride .. 2.8 to 6
Vinyl alcohol 1.8 to 2.0
Water, 20°C ............. 80
Water, 100°C ........... 48
Components:
The
LVP
‐
51
‐
R
is
offered
in
three
different
models.
Depending
on
the
model
purchased,
you
may
or
may
not
have
been
shipped
all
the
components
shown
below.
LVP
‐
51
‐
R
o
LVP
‐
51
‐
R
–
PSO
body
with
PP
cable
Quick
Start
Guide
