tional maintenance personnel for
Compass
and
carrying
case
for
disposition in accordance with the
completeness and general appear-
maintenance allocation chart (app.
ante. Inspect the compass and car-
rying case as outlined in table
(2) P r o c e d u r e . V i s u a l l y
examine
the
I.
Operator's
inspection
Chart
for
Compass
M2
and
Carrying
Case
M19
Fig
Point
of
Accepted
standard
no.
Inspection
Compass
M2
Rotate
the
azimuth
scale
adjuster
with
a
screwdriver,
alternately
in
one
Azimuth
scale
direction
and
then
another,
until
the
stops
are
reached.
The
scale
shall
adjuster
assy
move
freely
800
mils
in
either
direction
from
zero
without
binding
or
excessive
looseness.
Operate
the
level
lever
to
determine
if
there
is
sufficient
to
hold
the
Angle
of
sight
elevation
scale
index
at
any
setting
on
the
scale.
level
lever
Press
the
needle
lifting
(locking)
pin
down
until
its
end
is
flush
with
the
Magnetic
compass
body.
Note
the
position
of
the
magnetic
needle
with
respect
to
the
needle
azimuth
scale.
Gently
shake
the
compass
while
holding
the
needle
lifting
(locking)
pin
in
this
position.
There
shall
be
no
noticeable
movement
of,
the
needle.
Open the c o v e r
to
an
angle
of
approximately
60
with
the
face
of
the
com-
Alinement
of
pass.
Move
the
front
and
rear
sights
so
that
the
tips
make
contact
with
sights
each
other
to
assure
that
both
sights
are
in
alinement,
and
then
move
the
tip
of
the
rear
sight
along
the
etched
line
of
the
mirror.
The
tip
and
line
should
not
be
misalined
more
than
the
width
of
the
line
to
the
left
or
right.
Carrying
Case
M19
Snap
button
One
snap
button
shall
be
secured
in
the
carrying
case
and
shall
properly
hold
the
cover
flap
in
a
secure
and
closed
position.
The
loop
of
the
carrying
case
is
secured
by
rivets
to
the
back
side
(not
Loop
shown
in
the
illustration
indicated).
It
shall
be
securely
fastened
to
the
case.
b. Orientation. Allowance for declina-
13. Operation
tion constant can be made in the compass
a.
Setting Up. The compass should be
by shifting the azimuth scale, using the
held
as rigidly as possibie to obtain the
azimuth scale adjuster (fig. 3). The slotted
most
accurate readings. The use of a sit-
head of the adjuster can be turned with a
ting
or prone position, a rest for the hands
suitable screwdriver.
or
elbows,
or
a
solid
support
for
the
c. Measuring Azimuth Angles. To read
compass will help to eliminate uninten-
the azimuth scale by reflection, hold the
tional movement of the instrument. The
compass in both hands at eye level with
time of oscillation of the needle can be
arms braced against body and with the rear
shortened by partially depressing the
sight nearest the eyes. Place the cover at
needle lifting locking pin, or by using the
an angle of approximately 45 to the face
average position of the needle in its swing.
of the compass (fig. 4) so that the scale
When sighting, hold hands rigid and turn
reflection can be readily viewed in the
the body.
mirror. Level the instrument by viewing
Caution: When measuring angles in azi-
the circular level in the mirror, sight on
muth, no magnetic materials should be in
the desired object through the window,
dose proximity to the compass during the
and read the azimuth indicated on the re-
procedure.
flected azimuth scale by the south-seeking
7
Previous Page
