FCA
‐
22
Instruction
Manual
Page 18
Maintenance
Free
Chlorine
Sensor
Check
the
measurement
at
regular
intervals,
at
least
once
a
month.
If
the
membrane
is
visibly
soiled
clean
it
with
a
jet
of
water
or
a
dilute
HCl
solution
between
1
‐
5%.
Do
not
clean
with
detergents
or
solvents
that
would
reduce
the
surface
tension
of
the
membrane.
Replacing
the
Membrane
(PN
1000238)
Replace
the
membrane
if
heavily
soiled
or
torn.
First
unscrew
the
measuring
chamber
and
then
unscrew
the
membrane
cap.
(See
figure
5.1)
Remove
the
membrane
from
the
cap,
replace
the
membrane
and
reinstall
the
cap
on
the
measuring
chamber.
Finally
Refill
the
measuring
chamber
as
described
below.
Refilling
the
Sensor
Refill
the
sensor
with
electrolyte
once
a
year
or
sooner
depending
on
the
chlorine
level
measured.
Refill
every
6
months
for
levels
between
10
–
20
ppm
and
at
every
membrane
change.
Unscrew
the
measuring
chamber
from
the
sensor
and
pour
out
the
spent
solution.
Fill
the
chamber
to
approximately
1
cm
from
the
top
and
tap
it
gently
to
dislodge
any
trapped
bubbles
inside
the
chamber.
Screw
the
measuring
chamber
vertically
back
onto
the
sensor
ensuring
all
air
inside
the
chamber
is
displaced
with
liquid.
When
the
o
‐
ring
begins
to
seal
continue
slowly
tightening
until
the
stop.
The
sensor
is
ready
to
use,
re
‐
polarize
the
sensor
for
60
minutes
and
recalibrate
as
described
above.
Storage
The
method
for
Storage
of
the
sensor
is
dependent
on
time.
For
short
term
storage
of
several
weeks
the
sensor
can
be
stored
filled
inside
the
yellow
protective
cap
as
long
as
the
membrane
is
not
allowed
to
dehydrate.
Make
sure
the
sponge
inside
the
cap
is
wetted.
For
longer
terms
rinse
out
the
electrolyte
with
distilled
water
and
allow
the
sensor
to
dry.
Loosely
reassemble
the
dry
sensor
so
as
not
to
tension
the
membrane
during
storage.
1.
Measuring
Chamber
2.
Membrane
3.
Membrane
Cap
Figure
5.1