18.104.22.168 Field of view.- While observing through the elbow assembly
the 110 milliradian marks on the target image shall be visable to meet
the requirements of 3.6.12.
22.214.171.124 Projected reticle pattern.
126.96.36.199.1 Reticle lmage.- The elbow assembly reticle projector
and image tube shall be energized by the application of .18 VDC (reference
Drawing F11733401). The image of the projected reticle pattern image
shall be well defined and clearly visible when viewed with the unaided
eye to insure compliance with 188.8.131.52a and 184.108.40.206b.
220.127.116.11.2 Reticle accuracy.- The angular value between the bore-
sight cross and maximum range graduation of the projected reticle pattern
shall meet the requirement of 18.104.22.168 when measured on the target
22.214.171.124 Cleanliness, dirt.- The reticle projector lamp and the
image tube shall be energized during this test. Prior to performing the
test, the image tube shall be permitted a stabilization period of 15
seconds. Subsequent to the tube stabilization period, obtain best focus
of the phosphor grain on the screen of the image tube by adjustment of
the eyepiece diopter knob. The screen surface of the image tube shall
then be visually inspected for cleanliness in accordance with 3.7b and
shall conform to the requirements specified therein. "Cold " and "Hot"
spots on the screen surface of the image tube shall not be considered
4.6.7 Cleanliness, defects.- Remove the elbow assembly from the
testing equipment. The reticle projector lamp and the image tube shall
be deenergized for this test. With two 15 satt desk fluorescent lamps
held close to the objective window and eyelens, view by reflected light
the glass components of the body assembly utilizing the technique of
shadowing to determine compliance with the cleanliness requirements of
CAUTION: Prolonged exposure of the image tube to direct rays of
white light shall be avoided.
4.6.8 Sealing.- This test shall be performed utilizing a pressure
gage capable of reading between 0.25 to 0.50 pound per square inch gage
(psig) and a dew point tester. The following test sequence shall be
adhered to. Check the internal pressure of the elbow assembly utilizing
the pressure gage specified herein. Then, test the dew point of the
interior atmosphere of the elbow assembly by means of the dew point"
tester. Interior atmosphere of the elbow assembly shall conform to the
requirements of 3.8. Upon satisfactory completion of this portion of
the test, internal equipment conforming to 126.96.36.199.1. Pressurize the
elbow assembly with dry nitrogen gas, havign a dew point at least as low
as minus 25 degrees Fahrenheit, to 5 pound per square inch (psi), in
accordance With the procedure for internal testing on Drawing F8565556.