5-2
5-1 ZEROING OPERATIONAL DEFECTS
Operational defects relate to the relia bility of the image intensi-
fier and are an indication of instab ility. If identified, they are an
immediate caus e for rejecti ng the ATN NVM-14. They include
shading, edge glow, flashing, flickering, and intermittent opera-
tion.
A. SHADING
If shading is persistent, you will not see a fully circular im age
(Figure 5-1). Shading is very dark and you cannot see an image
through it. Shading always begin s on the edge and migrates
inward eventuall y across the e ntire image a rea. Shading is a
high contrast area with a distinct line of demarcation. Return the
ATN NVM-14 to the maintainer.
Figure 5-1
Shading
NOTE
Make sure the sh ading is not the result of improper eye -relief
adjustment.