‐
18
‐
Velocity
measurement
Sometimes
the
sound
velocity
of
a
material
is
not
known.
In
this
case
a
sample
with
a
known
thickness
can
be
used
to
determine
the
sound
velocity.
It
would
be
very
handy
to
carry
a
set
of
mechanical
calipers
to
use
in
conjunction
with
the
DC
‐
5000
in
the
field.
The
following
steps
outline
how
to
enable
and
set
up
this
feature:
1)
Physically
measure
an
exact
sample
of
the
material
or
a
location
directly
On
the
material
to
be
measured
using
a
set
of
calipers
or
a
digital
micrometer.
2)
Apply
a
drop
of
couplant
on
the
transducer
and
place
the
transducer
in
steady
contact
with
the
sample
or
actual
test
material.
3)
The
display
should
show
a
thickness
reading(probably
incorrect).
4)
Having
achieved
a
stable
reading,
remove
the
transducer.
(If
the
Displayed
thickness
changes
from
the
value
shown
while
the
transducer
Was
coupled,
repeat
step
3.)
5)
Press
the
key
to
illuminate
SET,
Use
keys
to
scroll
through
the
sub
menu
items
until
Velocity
Measurement
is
highlighted.
Press
the
key
to
confirm.
6)
Press
the
or
key
to
move
the
cursor,
press
the
or
key
to
adjust
the
displayed
velocity
up
or
down,
until
the
thickness
value
displayed
matches
the
thickness
of
the
sample
piece.
And
now
the
displaying
sound
velocity
value
is
accurate.
7)
Press
the
key
to
confirm
and
store
it
into
Velocity
Storage,
8)
Press
the
or
key
to
Illuminate
the
target
place,
Press
the
key
to
confirm.
9)
Press
the
key
to
exit
setting
and
DC
‐
5000
is
now
ready
to
perform
measurements.
