ATN PS-40 Operator's Manual page 39

Table 4-1. Preventive Maintenance Checks and Services
SEQ. ITEM TO
NO. CHECK
Battery
5 Compart-
ment
Function
6
Switch
7 Lenses
Objective
8
Lens
Focus
9
Ring
CHECKING PROCEDURE
Check for corrosion,
springs tension, cap
damaged or retainer
broken. Check O-ring
for cuts or damage.
Check for operation
(without battery).
Inspect for cleanli-
ness, scratches, chips
or cracks. Clean as
required.
Check to ensure the
objective lens is not
loose.
Check to ensure:
— the focus ring can-
not be moved along
the sight body;
— there is free rotation
through full range of
travel (3/4 turn);
— driving ring and
threaded ring (see
Figure 3-1) are rotated
together.
NOT FULLY MISSION
CAPABLE IF:
Springs corroded
or damaged. Re-
tainer broken. Cap
or O-ring damaged
or missing.
Switch inoperative.
Knob missing.
Chipped, cracked
or if scratches hin-
der vision through
the sight.
Objective lens
loose.
Focus ring moves
along sight body or
bounded. Driving
ring rotates while
threaded ring does
not move. That
affects ability to
focus properly.
4-3