Operation Manual

2-17
There are two groups of “defects” you may encounter – operational
defects and cosmetic blemishes. Operational defects are an im-
mediate cause to reject the MUNVM. Cosmetic blemishes are not
a cause for rejection unless they become severe enough to inter-
fere with the ability to perform the mission. The rejection of any
MUNVM for cosmetic defects must be based on an outdoor
evaluation and not the TS-4348/UV Test Set.
b. Operational Defects
These defects relate to the reliability of the image intensifier and
are an indication of instability. If identified, they are an immediate
cause for rejecting the MUNVM. They include shading, edge glow,
flashing, flickering, and intermittent operation.
(1) Shading. If shading is present, you will not see a fully circular
image (see Figure 2.3). Shading is very dark and you cannot see
an image through it. Shading always begins on the edge and mi-
grates inward eventually across the entire image area. Shading is
a high contrast area with a distinct line of demarcation. Return the
MUNVM to the maintainer.
FIGURE 2.3. SHADING
NOTE
Make sure the shading is not the result of improper eye-relief
adjustment (refer to paragraph 2.4.2).
(2) Edge Glow. Edge glow is a bright area (sometimes sparkling) in
the outer portion of the viewing area (see Figure 2.4).
SHADING