Zeroing Operational Defects; Shading - ATN PS-27 Operator's Manual

3.1. ZEROING OPERATIONAL
DEFECTS
Operational defects refer to the reliability of the image intensifi-
ers and are an evidence of instability. Their identification shall be
a valid reason to immediately refuse to accept the ATN PS-27.
These include shading, edge glow, flashing, flickering, and inter-
mittent operation.

3.1.1. SHADING

If shading is persistent, you will not see a fully circular image
(Figure 3-1). Shading is very dark and you cannot see an image
through it. Shading always begins on the edge and migrates in-
ward eventually across the entire image area. Shading is a high
contrast area with a distinct line of demarcation. Contact ATN or
point of purchase for warranty/repair procedures.
NOTE
Make sure the shading is not the result of improper exit pupil
position.
3-2
Figure 3-1
Shading