ATN ATN PS28, Operator'S Manual

Page: 38 / 48

3-6
3.1.2. INSPECTION CRITERIA FOR PROPER IMAGE
INTENSIFIER OPERATION
A. General
As directed in the Preventive Maintenance Checks and Services
table, image intensifier operation must be checked before each
mission. This section provides information for the operator con-
cerning what to look for, how to look for it, and how to determine if
the NVFS should be returned to the maintainer.
CAUTION
Perform the following inspection in the dark.
To perform this inspection, attach the sight to the daytime scope
as described in paragraph 2.1.3. and turn the function switch to the
ON position. Look through the monocular and view the image.
There are two groups of “defects” you may encounter – operation-
al defects and cosmetic blemishes. Operational defects are an
immediate cause to reject the NVFS. 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
NVFS 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 NVFS. They include shading, edge glow,
flashing, flickering, and intermittent operation.
FIGURE 3-1. SHADING
SHADING