Precision level
RESTRICTED
Fig. 64
amount it moved in step
8. Tighten
screws in sight stem locking plate
and recheck your work.
F.
PRECISION LEVEL. (CHECK PRECISION LEVEL FOR
ACCURACY: TAKE SPECIAL PRECAUTION WHEN USING LEVEL
NOT TO BREAK IT. NEVER PLACE LEVEL WHERE IT MAY
ACCIDENTLY BE BROKEN.
USE DRIFT PUNCH TO TIGHTEN
TURRET NUTS.
TIGHTEN FIRMLY BUT NOT ENOUGH TO
BREAK GLASS) .
Pace
adjustable surface plate on some
solid
base which
is
approximately level.
2.
Level precision
level by adjusting sur-
face plate.
Mark position of level
Con
plate
SO
that level may be
positioned
in the same place
relation to the surface plate.
3. Turn level 180° and note error.
4. Remove half the error by making adjustments
30, 0: 0024
on surface plate; remove other half of
error by
adjusting turret nuts on precision level.
5. Check by turning level 180°. If error
is
noted
, repeat step 4.
6.
Continue
until 180° turn causes no error
or causes equal apparent error.
7.
Level must set on perfectly true surface,
free
from dust.
G. Level Head of stand.
1.
Remove sight and stabilizer.
Place adjustable 3-legged
table on head
of stand.
3.
Place
3-legged surface plate on table.
4.
Using precision
level, adjust table to
bring plate horizontal.
5.
Place
length of
bubble tube (on surface
plate) parallel to a line between two mounting
bolts in base of stand.
Turn
of bubble movement from zero.
head of stand 180° and note amount
7.
Correct for 1/2 of this
movement with bolts
base of
stand.
Relevel surface plate with adjustable table.
Turn head of stand back 180°
note bubble movement from zero. There should be
none,
but 1:
there is, repeat step 7, and recheck.
Repeat
until there is no bubble movement.
in
2.
of
bubble
movement
from
through
187