2.1.3
Special Tools
One set of special tools, calibration devices, and instruments required for
operation, calibration, and maintenance of the equipment shall be provided
as follows:
[SELDS Test Set]
[_____]
2.1.4
Testability
Equipment and materials of the EM shielding shall be designed and built to
facilitate testing and maintenance.
2.2
EM SHIELDING EFFECTIVENESS
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NOTE: The designer will consider the shield as
early in the design as possible while the geometry
of the shielded enclosure can be located to utilize
components inherent in the structure. Failure to
consider the shield configuration first in the
design will increase design costs, cause problems in
its incorporation into the structure, and lose
installation simplicity. The EM shielded enclosure
design should be coordinated by the structural,
mechanical, and electrical engineers and architect.
The structural and shielding systems should drive
each other on large projects. Multi-story shielded
enclosures require continuous connections of
shielding steel interconnected to the structural
steel. In these cases, the shielding wall layout
should coincide with the structural steel beam
layout. The shield within an exterior building
concept must employ a design which allows for
settling, seismic motion, and differential thermal
expansion between the steel and concrete of the
building and the steel of the EM shielding.
**************************************************************************
The EM shielded enclosure complete with all filters, doors, and/or
waveguides shall have the following minimum EM shielding effectiveness
attenuation. Minimum magnetic field attenuation shall be [20 dB] [_____]
at 14 kHz increasing linearly to [50 dB] [100 dB] at [200 kHz] [1 MHz]
[_____]. Minimum electric field and plane wave attenuation shall be [50
dB] [100 dB] [_____] from 14 kHz to [1 GHz] [10 GHz] [_____].
2.3
EM SHIELDING ENCLOSURE REQUIREMENTS (WELDED CONSTRUCTION)
**************************************************************************
NOTE: For the EM shielding enclosure, choose either
welded or bolted construction. The unused method
should be deleted from the project specification.
Welded construction will usually consist of
continuous 1.897 mm (14 gauge) thick steel plate and
angles to form the enclosure. Thicker material may
be used if it is more cost-effective or required for
structural reasons. Welded construction is used
SECTION 13095A
Page 16
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