1
I.
Introduction
A.
General
Description
The
MS4500E
is
a
hand
‐
held,
battery
powered,
corrosion
meter
capable
of
measuring
and
storing
data
from
all
types
of
electrical
resistance
(ER)
corrosion
probes.
The
instrument
is
light
weight,
microprocessor
‐
based,
and
features
a
simple,
menu
‐
driven
interface
using
a
keypad
and
a
backlit
graphical
LCD
display.
Corrosion
rate
measurements
are
made
using
the
electrical
resistance
method.
Essentially,
the
instrument
measures
the
resistance
of
the
probe
element
which
changes
over
time,
as
metal
loss
occurs.
The
rate
of
change
is
directly
proportional
to
corrosion
rate.
This
method
finds
a
wide
variety
of
applications
since
it
can
be
used
in
conductive
and
nonconductive
environments
such
as
petroleum,
chemical,
water,
soil,
or
even
atmosphere.
The
new
high
‐
resolution
measurement
of
the
MS4500E
detects
smaller
increments
of
metal
loss,
providing
faster
response
than
traditional
ER
instruments.
After
taking
a
reading,
the
instrument
displays
metal
loss
in
mils
and
corrosion
rate
in
mils
per
year
(mpy).
The
reading
can
then
be
stored
to
memory
or
discarded.
All
stored
readings
are
automatically
time
and
date
stamped.
Readings
are
stored
to
non
‐
volatile
Flash
memory
which
retains
data
without
the
need
for
a
battery
backup.
The
MS4500E
High
Resolution
ER
Data
Logger
can
store
16,000
readings
per
probe
on
up
to
250
different
probes
(4
million
total).
Stored
data
can
be
downloaded
directly
to
a
USB
Flash
(“jump”)
drive
in
non
‐
hazardous
areas.
Data
can
be
opened
and
charted
using
the
provided
CDMS
software,
or
can
be
imported
into
any
standard
data
analysis
(spreadsheet)
program
such
as
Microsoft
Excel.
Data
can
also
be
reviewed
and
charted
on
the
instrument’s
LCD
display
for
quick
reference.
B.
Principles
of
Operation
The
MS4500E
High
Resolution
ER
Data
Logger
operates
on
the
Electrical
Resistance
(ER)
technique
and
is
used
in
conjunction
with
an
ER
probe.
The
ER
probe
utilizes
a
resistive
sensing
element
manufactured
from
the
material
of
interest
(or
a
close
approximation)
which
is
exposed
to
a
corroding
environment.
This
is
called
the
Exposed
or
Corroding
Element.
The
resistance
of
the
Exposed
Element
is
directly
related
to
its
thickness,
so
as
the
element
corrodes
the
resulting
loss
of
metal
causes
a
proportional
increase
in
the
element’s
resistance.
The
probe
also
contains
an
internal
Reference
Element
which
is
used
to
compensate
for
the
influences
of
temperature
on
the
Exposed
Element.
The
MS4500E
High
Resolution
ER
Data
Logger
is
designed
to
work
with
any
standard
ER
probe,
but
it
is
recommended
that
Cylindrical
and
Large
Flush
type
probes
be
used
to
ensure
optimum
performance.
Their
physical
design
places
the
Reference
Element
in
closer
proximity
to
the
Exposed
Element
compared
to
other
probe
types,
providing
more
effective
temperature
compensation
and
thus
reducing
the
effects
of
thermal
noise.
