Marconi TF 933C User Manual

Take
the
dial
reading which should,
ideally,
be off scale
below -G.
A high
reading on
the dial
shows
leakage
which
may be in the
electrode
or
the
leads.
It can be
located by
removing
these pa
individually.
In
connection
with leakage
across the
electrode
face
it
is
injport:tnl to
rernember
the following
rule:
The
instrument
reading
on the
empty
test cell
(without plunge r)
should be at
least
10
divisions
below,
or
preferably
15 to 20
below,
the reading ol.)lained
wit.h
the
sample
in
position.
For testing
very dry
samples
the 'empty
t reading should bc below
0
but
for
normal use
a reading as high
as
25
is
tolerable.
Application
of
this
rule will
save
wasting time
on
unnecessary cleaning.
4.3 CLEANING
The test cell electrode must
be
kept
clean.
The
surface area in
the
vicinity of
the socket holes
and
especially
the
thin insulating
ring between the
annular
metal
electrodes
should
receive
particular
attention.
A
brisk
rub
with
a
dry
cloth
is usually
all
that is
needed but the
part may be
washed
with
water
and
may also
be
dried by
gentle
heat
(max.
50 o
c)
if
necessary.
It
is
inadvisable
to use
wax
polishes
to clean the
insulating
parts
of the
test cell,
as the
materials
from which
these
parts
are
constructed
are
superior
to
wax as a
water
repellent.
If
sticky
or oily substances
are
tested
as
a
matter
of
routine,
it is
advisable
to
have
one
or
two
spare
electrodes
which
can
be used
while the
others are
cleaned.
4.4
LUBRICATION
Keep
the
moving parts
of the
clamp
lubricated
and
free
from
grit.
The
ball-
and—claw
joint of
the
swivel
nose
should
be
washed
from time
to
time
to
remove
the
old
grease
and
dirt
and
relubricated
with
grease
or
heavy
oil.
The screw
should
be
cleaned
and
greased
occasionally.
Inadequate
lubrication
may
cause
rapid
wear and
will
make the
clamp
stiff:
it
should
be
possible
to
turn
the
tommy-bar
with
one finger
with the
clamp
at
the
'flush'
setting.
4.5
ACCESS
AND
LAYOUT
The
diagram
Fig.
4.1
illustrates
the
accessibility
of
the
components
of
the
Moisture
Meter
TF
933C.
Access
to the
replaceable
dry
batteries
is
explained
in
section
4.6.
18
9.3.'W
(1)

Marconi TF 933C Specifications

General

Brand	Marconi
Model	TF 933C
Category	Measuring Instruments
Language	English