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TM 9-254
9-6.
Inspecting Optical Components - Continued
(9)
Pit. A term denoting a small hole in the component surface, which can be seen as a small particle.
(10) Scratches. Any marking or tearing of the component surface appearing as though it had been done by
the sharp or rough edge of an instrument.
(11) Cement Separation. This condition shows up as jagged lines and yellowish areas between the elements
of a cemented lens.
(12) Smears. The faint, but visible traces of cleaning solution left on the optical component when the
cleaning procedure is improperly performed.
c.
Inspection Requirements. The requirements herein shall apply to initial and in-process inspection of optical
components.
NOTE
o Information contained in tables 9-2 through 9-6 has been extracted from Maintenance
Inspection Standard for Fire Control Materiel, MIS TOE 102 and Surface Quality Elements, part
number 7641866.
o The combined length of maximum size scratches cannot exceed the maximum length as
indicated in tables 9-2 through 9-6. This length is based upon the diameter of the lens.
(1)
Moisture and condensation. There will be no evidence of moisture, condensation, or staining resulting
from moisture.
(2)
Fractures. No fractures will be allowed on optical component surfaces.
(3)
Smears or Fingerprints. There will be no evidence of any smears or fingerprints on optical component
surfaces.
(4)
Chips. The presence of chips on optical components will be permitted provided they are honed and do
not extend more than 1/16 inch into the clear aperture of the component.
(5)
Scratches. Scratches will be permitted provided the total effect of such discrepancies do not exceed
that allowed in tables 9-2 through 9-6.
(6)
Digs, Pits, and Bubbles. Digs, pits, and bubbles will be permitted in accordance with criteria given in
tables 9-2 through 9-6.
(7)
Coating. Coating with not more than 25% deterioration will be acceptable provided the deterioration is
not concentrated in a given area. Crushes or rubs not heavily concentrated are permissible provided
they do not extend into the clear aperture of the component.
(8)
Cement Separation. Cement separation, once started, has a tendency to spread and therefore will not
be permitted.
9-21
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