MIL-PRF-38214D
3.5.5.3.2 Brightness. When a 4.5 ±0.050VDC power applied to the lighting terminals, the light
intensity and distribution shall be as follows:
a. White areas. 1.00 ±0.50 foot-lamberts. The average of all reading taken in the white
areas shall be 1.00±0.30 foot-lamberts.
b. Black areas. 0.05±0.03 foot-lamberts when reflected light (wedge and ring lighting) is
used and 0.04±0.02 foot-lamberts for refracted light (back lighting).
c. Pointer and lubber lines. 1.20 ±0.50 foot-lamberts. The average brightness of all the
pointer readings shall be 0.10 to 0.50 foot-lamberts higher than the average brightness of the dial
white areas.
3.5.5.3.3 Stray light. The lighting system shall be so housed as to prevent the leakage of stray
light and to shield the lamp filaments from direct view.
3.5.5.3.4 Light leakage. The lighting system shall in no way restrict the visibility of any
graduations, numerals, pointers, or other specified markings.
3.5.5.3.5 Contrast. Contrast between the white and black portions of the indicator scale shall be
12 or greater. Contrast, C, is defined as:
C= [B2-B1]/B1
Where: B2 is the brightness of the white, and B1 is the brightness of the black portion of the
instrument scale.
3.5.5.4 AQU-5/A, MS17983-4 AND MS17983-4/Y (red light). These compasses shall
incorporate an integral red lighting system as specified in MIL-L-25467.
3.5.5.5 Type III NVIS Green High Intensity Lighting. The compass shall incorporate an
integral, NVIS-compatible, green lighting system as specified in MIL-L-85762.
AQU-3/AN5 (low voltage) shall operate at a nominal voltage of 5VDC.
AQU-3/AN24 (normal voltage) shall operate at a nominal voltage of 24VDC.
3.5.5.6. 160J18047 (NVIS Green). This is a special application compass design tailored
specifically for the A-10 aircraft. The compass shall incorporate an integral, NVIS-compatible,
green lighting system as specified in Grumman Aerospace drawing ES220S0013. This compass
shall operate at a nominal voltage of 24VDC.
3.5.5.7 AQU-14/A (white light, low voltage). The compass shall incorporate an integral lighting
system and operating voltage as specified in MACAIR 91B0445.
3.5.6 Compensator (see 6.8).
3.5.6.1 Adjustability. The compensators shall be manually adjustable to remove the compass
deviations on north-south and east-west headings. Both compensators shall be provided with a
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