lighting, aircraft, night vision imaging system - General Dynamics ...

MIL-STD-3009
5.7.2.1 Resolution assessment using a USAF 1951 medium contrast target.
A USAF 1951 medium contrast resolution resolving power target (USAF Tri-bar Chart)
with a contrast modulation (Cm) of approximately 70% shall be used. The chart shall be
set up outside the mockup at a distance such that the test subject, while seated in the
aircraft in the appropriate operational position and wearing NVIS, is just capable of
resolving an element in a target group midway between the largest and smallest groups
when the chart is irradiated as specified.
5.7.2.2 Resolution assessment using a 50% contrast, square-wave grating NVG
resolution chart.
A square-wave grating pattern NVG resolution chart having a contrast modulation (Cm)
of 50% + 10% shall be used. The NVG resolution chart shall contain horizontally and
vertically oriented square-wave grating patterns that determine Snellen acuities of
20/20, 20/25, 20/30, 20/35, 20/40, 20/45, 20/50, 20/55, 20/60, 20/65, and 20/70 when
resolved at a viewing distance of 20 feet. The chart shall be set up outside the mockup
at a distance of 20 feet from the test subject and irradiated as specified.
5.7.3 Luminance uniformity.
5.7.3.1 Low level.
During the inspection, each lighting subsystem shall be energized independently to one
half of its rated voltage. A visual inspection shall be made to determine the brightest
and dimmest lighting component of that subsystem. Unless visual inspection has been
accepted for luminance uniformity by the acquiring activity, a photometer in accordance
with APPENDIX A shall be used to measure the luminance of the brightest and
dimmest lighting component.
5.7.3.2 High level.
Each lighting subsystem shall then be energized independently to maximum brightness.
A visual inspection shall be made to determine the brightest and dimmest component of
that subsystem. A photometer in accordance with APPENDIX A shall be used to
measure the luminance of the brightest and dimmest lighting component.
5.7.4 Crewstation reflections.
Examination for specular reflections shall be performed during inspection (see 5.7.1
and 5.7.2).
5.7.5 Visual examination.
Each lighting system, subsystem, or component shall be examined visually to
determine conformance with this document. Any evidence of foreign matter, cracks,
scratches, bubbles, delamination, warps or stray light shall be considered cause for
rejection.
5.7.6 Operation.
Each lighting system, subsystem, or component to be inspected shall be energized at
the same levels as measured in the system to determine that it operates in accordance
with this document.
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