 |
|||
|
|
|||
| ||||||||||
|
|  MIL-C-48550(AR)
within the collimator, the collimator shall be sealed with an in-
ternal pressure of nitrogen at a pressure of between 0.25 and 0.50
psig at room temperature.
4.5.3
Optical.
4.5.3.1 Reticle lean. - Reticle lean test shall be performed with
aid of a collimating telescope, hereafter referred to as auxiliary
telescope; with a reticle plumbed and adjusted to infinity focus.
Position the collimator in front of the auxiliary telescope so the
optical axis are coincident. Align the zero verticle line image
of the collimator parallel with the verticle reticle line of the
auxiliary telescope. with the zero verticle line image of the
collimator plumbed, the bubble of the level. vial shall be within
the central graduation marks of the vial in accordance with the
requirements of 3.4.3.1.
4.5.3.2 Reticle accuracy. - This test shall be accomplished with the
aid of an auxiliary telescope and calibrated reticle pattern. The
calibrated reticle pattern shall have a horizontal line 100 roils in
length with vertical marks at the center and each end. A mil block
at either end of the horizontal line will enable the observer to
detect error. With the auxiliary telescope focused on the colli-
mator reticle image, both 50 mil marks of the reticle image shall
coincide within the allowable tolerance in accordance with the require-
ments of 3.4.3.2.
4.5.3.3 Parallax- This test shall be performecl with the auxiliary
telescope positioned as specified in 4.5.3.1. Parrallax shall be re-
moved from the auxiliary telescope by means of auto collimator.
The
test shall be made by sighting through the auxiliary telescope to
the collimator center cross image. Parallax will be recognized as
any apparent displacement of the collimator center cross image in
relation to the auxiliary telescope reticle when the observer's
head is moved from side to side, or up and down. Any movement of
s
the observer heal shall not cause displacement of the collimator
center cross image to exceed the requirement specified in 3.4.3.3.
4.5.3.4 Cleanliness. - The optical system of the collimator unit
shall be inspected for cleanliness in accordance with Specification
MIL-O-13830 and 3.4.3.4 herein and shall meet the requirements
specified. Dirt particles which interfere with the legibility or
accuracy of the reticle pattern shall be cause for rejection. The
mean diameter of a size 10 dig is equal to 0.10 millimeter.
illumination. Perform test under daylight conditions
4.5.3.5 Reticle
with the rear cover of collimator in an open position. Position a
four power telescope at a distance of 15 feet (+6 inches) and then
at 48 feet (-6 inches) from the objective lens of the collimator.
At both positions view the collimator reticle through the telescope
for compliance with paragraph 3.4.3.5. Repeat the above test in a
completely darkened area; and with the rear cover closed
10
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals