be in coincidence with its respective target line, then the opposite end
of this reticle line must coincide with the opposite end of the target
line within the tolerance specified in 3.5.5 when viewed at the proper
eye distances. This tolerance is shown on the target as Mil Block "E"
of Figure 1. The equipment shall be capable of inspecting the optical
and mechanical axis of the reflex sight within 0.1 mil.
4.6.4 Focus and focus shift.- Establish the line of sight defined
in 3.5.3 and utilize a dioptometer whose entrance aperture is located
eight to ten inches from the vertical centerline of Objective 7648295.
Record the point at which the target and reticle image can be focused
along the line of sight and at four positions specified in 3.5.4. Verify
compliance to 3.5.3 and 3.5.4. When conducting this test, the target or
sight may be moved angularly in azimuth or elevation as required to bring
about alignment adequate to measure focus shift.
4.6.5 Temperature.- The test equipment to be utilized when perform-
ing the temperature test shall be such that the equipment under test
shall not exceed 50 percent of the internal volume of the test chamber
and no portion shall be closer than 6 inches from any surface of the
chamber. Plugs, covers, and inspection plates used in service shall
remain in place. When electrical or mechanical connections are not
utilized, the connections normally covered in service shall be adequately
covered. The equipment shall be installed in the chamber in manner
similar to its actual use in service. The reflex sights shall be tested
in accordance with Procedure 1, Temperature Cycling in Specification
NIL-F-13926 to meet the requirements as specified in 3.4.1.
4.6.6 Rain.- The equipment shall be mounted in a test chamber to
simulate installation conditions. The rain test chamber shall be capable
of maintaining a temperature of between 20°C to 30°C (68 °F to 86°F)
throughout the test period. A simulated rainfall as measured at the sur-
face of the equipment with a U.S. Weather Bureau type gage shall be pro-
duced by means of a water spray nozzle of such design that the water is
emitted in the form of small droplets rather than a fine mist. The
temperature of the water shall be maintained between 11°C to 20°C (52°F
to 68°F. The rainfall shall be dispersed uniformally over the test area
within the limits as specified above. Direction of rainfall shall be
variable from vertical to 45 ° from vertical in any direction. The simu-
lated rainfall shall be directed on all surfaces which are normally sub-
jected to rain and shall meet the requirements as specified in 3.4.2.
4.6.7 Optical component defects and cleanliness. - Subsequent to
conducting all tests and examinations and without sight dis-assembly,
perform a visual examination of all optical elements and areas between
elements to verify compliance to 3.5.6 and 3.5.7. This test shall be
performed by viewing in an illuminated area such as would exist by hold-
ing the sight in close proximity to a bench lamp containing two fifteen
watt daylight fluorescent tubes backed by a white reflector.
PREPARATION FOR DELIVERY
5.1 Packaging, packing and marking.- Packaging, packing and marking
shall be in accordance with the applicable Packaging Data Sheet specified