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Non-observance of the recommended form of MT strip edges can result in
stitching discrepancies and MT jamming in the MOV USB device. Use of polluted
and damaged MT leads to device malfunction.
To renew ethyl alcohol operating reserve, take the container for alcohol from the box
(Figure 7d), remove the cap, unscrew the head and pour about 5 ml of ethyl alcohol. Screw
the head of the container and put the cap back on its place.
2.2.2.3 MCAS intended use
The MCAS can be used after the requirements of paragraph 2.2.1 are fulfilled and the steps
described in paragraph 2.2.2.2 are completed.
Magnetic copying of an object using MCAS consists of the following steps:
z
preparing the examined surface,
z
selecting MT type,
z
preparing (demagnetizing) MT,
z
magnetic copying.
Selecting the MT type
The User is to select the MT type (metal or plastic) and width (1’’ or ½’’). The following
recommendations should be taken into consideration.
z
Plastic MT is considerably less expensive than metal MT. As technical properties of both
MT types are almost the same, plastic MT can be used in the majority of cases.
z
It is recommended NOT TO USE plastic MT in the conditions which worsen the quality
of magnetic copying and shorten MT lifetime, e.g. on very rough surfaces (severe
corrosion, premilling), on hot surfaces (when surface temperature e50 ˚C), on
surfaces with sticky stains that cannot be removed.
z
It is recommended TO USE plastic MT in the conditions which improve the quality of
magnetic copying, e.g. for examining the relief and structure of aluminum objects, for
examining weak internal stresses in ferromagnetic objects, for magnetic copying in
narrow openings and in grooves where the only way to avoid MT damage is to use ½’’
plastic MT.
Preparing the examined surface
z
Provide easy access to the examined surface: take off jackets, side plates, detachable
equipment.
z
Clean the examined surface from foreign particles (such as dust, dirt, sand, tar, etc.), as
well as from lubricant films. If necessary, clean it with ethyl alcohol, then dry or remove
moisture. Dirty MT slightly worsens the quality of magnetic copying, but it leads to
untimely magnetic tape wear. The particles adhered to the tape damage the magneto-
optical crystal and foul the tape-drive mechanism.
ATTENTION! DO NOT REMOVE RUST FROM THE SURFACE!
Rust layer, especially on the heavily corroded surfaces, often is the only remaining
carrier of information about original numbers.
Preparing (Demagnetizing) MT
z
Take the CMS out of the MCAS compartment.
z
Select a used (after visualization) MT strip.
z
Press and hold the demagnetizer drive button (Figure 8, pos. 1). Insert the end of
the MT strip (Figure 8, pos. 6) into the demagnetizer slot and slightly push it forward
until its end appears on the opposite side.
z
Release the demagnetizer drive button (Figure 8, pos. 1), take the threaded end of
the MT strip and pull it through the demagnetizer.
z
Use the demagnetized MT for carrying out a new magnetic copy or place it into the cartridge
for demagnetized MT (marked with green marker) (Figure 6a, b).
Summary of Contents for 7517A
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