EMI Shielded Vents0 pages
OurVH Shielding range of lightweight aluminium
honeycomb attenuating ventilation panels
comprise of forms of conductive airflow media
retained within an aluminium extrusion. They are
designed for use in racks and other forms of
commercial enclosure.
14
VENTSHIELD Attenuation Vents
VH Shielding
Applications:
Lightweight aluminium honeycomb vents can be mounted onto most
forms of shielded enclosure where airflow is needed, either over cooling
fans or by convection. They can be mounted anywhere on the enclosure
and can befitted with protective'kick-plates'to protect the honeycomb
material from accidental damage.
Where they may be exposed to the elements the vents can be fitted with
'slant' honeycomb which provides a downward facing aperture, prevent-
ing the ingress of rainwater. This has the added benefits of directional
airflow and increased attenuation due to the higher aspect-ratio of the
cell structure.
Honeycomb ventilation panels are usually supplied with gaskets in a
ready-to-mount form which either fits around the aperture in the
equipment (non-flanged style) or to be inset into the enclosure (flanged
style). Depending on the performance requirements for the application,
they can be mounted by bolting through clearance holes in the frame or
through the use of captive threaded inserts.
Aluminium honeycomb material is formed by expanding a bonded
aluminium foil into a honeycomb structure. This process, which is
common to all honeycomb manufacturers, produces a material which is
'polarised'and is conductive either horizontally or vertically. To overcome
polarisation problems two layers of honeycomb, mounted at 90 degrees
to each other, are used. Please contact us for further information about
polarisation.
Each cell in an attenuation vent acts as a waveguide and its performance
is a function of its width/height and the ratio between the depth and
width of the cell. Generally an aspect ratio of 4:1 or 5:1 is used.
Aluminium honeycomb vents are finished to suit specific applications
and can be protected by Alocrom 1000,1200 or electroplating. We can
also offer an Iridite conversion which is RoHS compliant.
Specifications:
For gasket material specifications please refer to knitted mesh gaskets
(pages 4-13), oriented wires in silicone gaskets (pages 20-22) and
conductive silicone gaskets (pages 39-42).
Performance: Typical Attenuation dB
1 m-rtMUiOGT ^
P&PTechnology Ltd
1-3 Finch Drive
Springwood Industrial Estate
Braintree CM7 2SF
T:+44 (0)1376 550525
www.p-p-t.co.uk
FREQUENCY
10 KHz
100 KHz
1 MHz
1 MHz
10 MHz
100 MHz
1 GHz
10 GHz
FIELD
H
H
H
E
E
E
P
P
ATTENUATION
45
49
51
>100
>100
>100
98
95
"