|
|
Products
Applications
1. R.F. shielding
Applications:
 Magnetic Resonance Imaging (MRI).
Medical equipment and instrumentation.
EMC product compliance testing.
Embassies and Military.
2. Magnetic shielding Applications:
Magnetic Resonance Imaging (MRI).
Magnetic radiation.
Electro Magnetic Field – EMF.
Architectural And Engineering Specifications
ARCHITECTURAL AND ENGINEERING
SPECIFICATIONS OF MAGNETIC
SHIELDING
1. MAGNETIC SHIELDING- RADIATION (AC)
This type of shielding is mainly used for application
where we have transformers, electric Board and electric
cables
1.1 ALUMINIUM SHIELDING LAYER
1.1.1 This layer is made from a low resistive alloy,
coated with Aldine, (or equal) and with passivation
against rust.
1.1.2 The Aluminum boards are connected together with an
overlap. The connection to the wall is made by screws threw a
plastic masonry anchor, to guaranty isolation.
1.1.3 The Aluminum construction is electrically
grounded, only by one or two connection points.
1.2 MAGNETIC STEEL SHIELDING LAYER
1.2.1 In order to achieve an efficient shielding, a
thick coating is needed. The layer is made from several
Steel plates to gain required thickness, the amount of
plates is determined specifically for each installation,
to ensure suitable protection.
1.2.2 the Steel layer is tightened, according to
manufacture instruction,
2. ELECTRO MAGNETIC FIELD (DC) SHIELDING
This shielding is commonly used in MRI APPLICATION in
order to REDUCE
Magnetic FIELD strength
2.1 This shielding uses soft Steel or Silicon Steel
(high permeability Materials)
plates and provides good protection for low frequency
Magnetic field (DC or static).
2.2 The thickness of the layer is determined by factors
like the
attenuation needed and the magnetic field's force.
ARCHITECTURAL AND ENGINERING
SPECIFICATIONS OF R.F. SHIELDED ROOMS
1.0 GENERAL
1.1 PERFORMANCE FUNCTION
The R.F shielded solid wall enclosure manufactured by
S.I.E Inc. shall .
be designed, manufactured, and installed to create
controlled environment in which radio frequency signals
are contained and/or excluded.
The R.F. shielded enclosure shall conform to the
industrial standards in general as indicated in mil std
- 285, NSA-65-6, MIL STD-220A, in addition, it shall
comply with attenuation requirements of any
manufacturer's previously specified equipment to be used
within the R.F. enclosure.
Shielding effectiveness shall be considered for the
complete enclosure including all the accessories
specified with the R.F. enclosure.
1.2 SHOP DRAWING AND FIELD MEASUREMENTS
A complete set of drawings showing layout, wall
elevations, dimensions, and certain details indicating
interaction with other trades shall be submitted for
approval before starting the fabrication of materials.
When possible, field measurements shall be taken to
verify or supplement the indicated dimensions.
1.3 COORDINATION
Work shall be specified and coordinated with other
trades performing related work with regard to limits and
obligations, and to the locations of connections for
parent piping, ducts, conduits junction boxes, etc
2.0 SHIELDED
ELEMENTS
2.1 R.F. SHIELDED SUBFLOOR
The parent room floor recess shall be covered with four
mm. polyethylene vapor barrier, an electrical isolation
layer of hardwood laminated to the copper shielding,
and. an interconnected plywood floor course.
2.2 R.F. SHIELDED WALLS AND CEILING PANELS
2.2.1 Type A
The modular R.F. shielded panels for walls and ceiling
shall be rigid and self - centered. Panels shall provide
electrically isolated' shielding with an interior copper
facing.
The interconnected panels shall be continuously soldered
. Ceilings may be self - supporting or maintained by non
- magnetic hangers from the parent structure.
Maximum allowable deflection under load shall not exceed
1/240 of the panel span. When specified, provision shall
be made for removable panel sections to facilitate
access to and removal of large equipment such as the
magnet
2.2.2 Type B
The panels are laminates of electrolytically deposited
zinc, sheet metal laminated to both surfaces of 1/4 inch
structural core. Wall, floor and ceiling panels are of
the same construction.
The panels are joined and supported by specially
designed members that clamp the edges of the panels
and provide constant, low impedance joints with the
shielding elements of the panels.
The steel framing-joining system consists of four types
of channels: "M", "U", "hat" and "flat", with the "M"
and "U" channels forming the corner joints and the
"hat" and "flat" channels forming the intermediate
joints. These channels are made of 1/8 inch zinc-plated
steel and have eleven grooves or serrations running
lengthwise along each side of the contacting surface.
The "M" and "hat" channels have weldnuts welded to the
inside of the channels on 3-inch centers. The "U" and
"flat" channels have holes punched on 3- inch !centers
to correspond to the positioning of the weldnuts.
The "flat" channel has a convex contour for positive
spring tension, insuring and R.F. tight enclosure. Screw
fasteners of either zinc-plated or cadium-plated steel
1/4-inch in diameter are provided to complete the
assembly. These screws fasteners do not penetrate the
"M'" or the "hat" channels.
At all corner intersections of walls, floor or ceiling,
a one piece factory pre-welded corner section is
provided. This corner consists of sections of "M" and
"U" channels welded together and zinc-plated.
The entire steel frame work is supplied with integral
interconnecting tabs and weld screws and is assembled
from the interior using only a posi-drive head
screwdriver.
This interconnecting system enables rapid assembly and
installation of the enclosure.
2.3 R.F. SHIELDED DOORS
2.3.1 Type A
The shielded door shall have a .minimum clear opening
of 48 inches by 84 inches
unless otherwise specified The door unit shall be
factory assembled complete with door leaf, door frame,
threshold hardware, and electrical contact strips
(''Fingerstock").
A brass extrusion is mounted on three sides of the door
frame.
This extrusion houses two rows of fingerstock which are
concealed from accidental damage. The door itself except
for the threshold sill has a knife-edged extrusion
around the perimeter which mates with the fingers within
the frame when the door is closed.
The threshold sill shall be R.F. sealed by means of two
rows of fingerstock attached to the door. The two
surfaces, door and threshold sill shall be sloped
providing flush passage for wheel chairs and beds and
simul taneously assuring protective spacing for the
fingerstock expansion. The door shall be faced inside
and out with a hard wood veneer, solid vinyl, or as
otherwise specified per arrangement.
The door shall be provided with a three point latching
mechanism completing the R.F. seal and operable from
both sides of the door by a handle which will not
mechanically interfere with the door frame when the
shielded door is opened or closed and which shall
require less than 20 pounds to perform this action. The
door shall be equipped with three non-ferrous hinges.
2.3.2 Type B
To achieve the attenuation levels required, our doors
are equipped with a minimum of two rows of beryllium
copper ''fingers'' around the periphery of the door. In
the closed position, the fingers contact the door frame
to assure an RFI/EMI leak-proof seal.
A brass extrusion is mounted on the periphery of the
door frame.
This extrusion houses two rows of ''fingers'' which are
concealed form accidental damage. The door itself has a
"knife-edged'' extrusion around it's perimeter which
mates with the fingers within the frame when the door is
closed. This design results in a damage-free closure
seal with highly efficient prevention of RFI/EMI
leakage.
Latching Mechanism
The enclosure doors are equipped with a 3-point latching
mechanism for tight, RFI-EMI-secure closing. Bearing
surfaces, rollers and door cams are of case-hardened
tool steel, designed to provide years of trouble-free
operation with no loss of attenuation capability due to
friction and wear. Our doors are extremely easy to
operate; they require less than 20 pounds of force on
the handle.
Sizes available
Our standard single-personnel-door
provides a 3'0" by 7'0" high clear opening and our
standard double door provides 6'0" by 7'0" clear
opening. In addition any size door may be supplied on
special order to meet particular customer requirements.
Automatic Doors
SIE can supply shielded doors with power operated
latch/unlatch mechanisms-also, fully automatic doors
with open and close cycling.
2.4 R.F. SHIELDED WINDOW
Each R.F. shielded enclosure unless otherwise specified
shall include a shielded window with a clear opening of
60 inches by 30 inches which shall include two layers of
glass enclosing the copper screen shielding material
within the dead air space created by the double glazed
assembly. The glazing material shall be clear float
glass 1/4 inch thick. The total window assembly shall
maintain effective R.F. shielding equal to that of the
shielded room.
2.5 HVAC R.F. SHIELDED PENETRATIONS AND SERVICES
A minimum of one air inlet and one exhaust outlet of
R.F. Shielded "honeycomb" shall be provided. These
waveguide type air vent filters shall provide proper air
passage for cooling, heating, and ventilation while also
maintaining effective R.F. Shielding and equal to that
of the shielded room. Collars and Nonconducting boots
shall be supplied and installed to the parent
ductwork. Likewise suitable collars and boots shall be
furnished and installed to differs or grills in the
suspended ceiling of the shielded room.
2.6 R.F. SHIELDED ELECTRICAL AND COMMUNICATION
SERVICES
2.6.1 R.F. SHIELDED POWER LINE FILTERS
Power line filters when specified shall be of the
required voltage and current rating and shall provide
the proper attenuation to conform with the shielded room
specifications. The filtered conductor shall penetrate
the enclosure through waveguide
penetrations, an integral part of the filter. The
insulated loss of the filter is a full 100 LB PER MIL
STD - 220A in 10 the frequency range of 100 KHZ to GHZ .
2.6.2 R.F. SHIELDED SIGNAL LINE FILTERS
Signal line filters when specified shall be of the
proper characteristics for telephone service, data, or
other communication functions and shall provide the
proper attenuation to conform with the shielded room
specification.
2.6.3 R.F. ENCLOSURE GROUNDING
Each shielded enclosure shall be supplied with a
permanently grounded stud on the exterior surface of the
enclosure. A grounding bus wire shall be connected to
the building electrical ground to ensure on - ground
reference and to eliminate any possible ground loops
within the enclosure.
2.7 EQUIPMENT MANUFACTURER'S PENETRATION PANEL
When specified any filter plates, R.F. Plates, or
penetration panel supplied by the manufacturer of
previously specified equipment to be used within the
R.F. Enclosure shall be integrated into the specified
position of the R.F. Enclosure while maintaining the
effective R.F . Shielding.
2.8 R.F. SHIELDED PLUMBING SERVICES
The R.F. Shielded enclosure shall be provided with the
proper penetrations for water, gases, vacuum and waste
when specified. These penetrations shall not impair the
total shielding effectiveness of the enclosure. If
specified the supply and installation of the piping from
the parent source of the above elements and their proper
end capping or fixtures can be provided together with
the R.F. Shielded enclosure.
3.0 INTERIOR
FINISHES
3.1 FINISHED FLOOR
Unless otherwise specified, the floor of the R.F.
shielded enclosure shall be finished with a solid vinyl
tile conforming to federal specification SS-T-312B. If
specified a seamless or regular conductive vinyl tile, a
conductive of regular carpet, or a raised computer type
floor in any of the above mentioned finishes can be
supplied as per arrangement. All elements of the raised
floor shall be of nonmagnetic material. In addition to
the above a vinyl cover base shall be provided.
3.2 FINISHED WALLS
A network of 2x4 inch nominal fire treated studs shall
be provided within the enclosure to accept gypsum board
with paint or vinyl finish and to receive mechanical and
electrical utility boxes. The gypsum boards shall be
fixed by means of non -magnetic fasteners. Other
possible finishes can be supplied as specified per
arrangement.
3.3 FINISHED CEILINGS
Unless otherwise specified, the R.F shielded enclosure
shall be provided with a suspended acoustic ceiling of
24x24 inch mineral fiber panels within an all aluminum
"T" grid. The entire suspension system shall be of
non-magnetic materials
4.0 R. F.
TESTING
The R.F. shielded enclosure shall be tested to
demonstrate the R.F. attenuation in compliance with the
MIL-STD-285. Testing will be carried out at a minimum of
one location on each wall and before any finished
material has been erected within the shielded enclosure.
An acceptance test shall be performed after completion
of the finished room prior to occupancy by the owner.
5.0 WARRANTY
The enclosure shall be guaranteed against defective
materials and workmanship and to retain the specified
R.F. shielding characteristics for a period of five
years from the date of the acceptance test except for
moving parts such as the door which shall have a one
year warranty.
|
|
|
