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TM 9-254
9-6.
Inspecting Optical Components - Continued
(9)
Polished Surfaces. Polished optical surfaces will show no evidence of grayness or stains.
(10) Reticles. The reticles will have no more than five pits, digs, or bubbles, no bigger than the smallest
reticle line, over the entire surface of the reticle.
Table 9-2. Prisms and Mirrors
Estimated
Number of
Scratch
Maximum
Number of pits,
Size of pits,
diameter
scratches
size
length
digs, bubbles
digs, bubbles
up to 1.250
4
60
1/5
4
40
1.251 - 2.250
6
60
1/4
5
40
2.251 - up
8
60
5/16
6
40
Table 9-3. Field Lenses *
Estimated
Number of
Scratch
Maximum
Number of pits,
Size of pits,
diameter
scratches
size
length
digs, bubbles
digs, bubbles
up to 1.250
3
60
1/8
3
10
1.251 - 2.000
3
80
3/16
3
20
2.001 - up
3
80
1/4
3
40
* Under no condition will scratches and pits, in the central area of the lens (25X of lens surface) be greater than that
shown.
Table 9-4. Eye Lenses
Estimated
Number of
Scratch
Maximum
Number of pits,
Size of pits,
diameter
scratches
size
length
digs, bubbles
digs, bubbles
up to 1.250
3
60
1/8
3
20
1.251 - 2.000
-5
60
3/16
5
20
2.001 - up
8
60
1/4
8
20
Change 2 9-22
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