TM 11-5855-239-23
and replacement.
b. Tip the metascope so that the image tube
slides part way out.
a. Remove the retainer wire.
c. Hold the metascope in one hand and firmly
pull the image tube out with the other hand. It
b. Unscrew the objective lens counterclock-
may be necessary to slightly rock the image tube
wise.
past the alignment ring.
c. Inspect the lenses for scratches, chips, or
d. Remove the contact ring. Inspect it for dam-
breaks. Clean the lenses with lens tissue of a soft
age or corrosion. Replace if necessary.
lint-free cloth.
d. Replace the parking ring if the rubber has
e. Clean the corrector lens (located at the
deteriorated or is damaged. Lubricate the new
end of the tube housing) with lens tissue or soft
packing ring with pneumatic grease MILG
lint-free cloth.
4343.
f. Clean the image tube if necessary with a
e. Clean the corrector lens (located in
soft lint-free cloth.
metascope housing) with lens tissue or a soft
g. Test the image tube by replacing it with a
lint-free cloth.
new one.
f. Screw the objective lens all the way in
h. When you replace the contact ring and
the metascope housing.
image tube make sure they are correctly orien-
g. Insert the retainer wire.
tated as it is possible to install them backwards.