Datasheet

3636
RFI/EMI shielding
for enclosures
Ensto has many years of experi-
ence in creating a good protection
against interference in onerous lo-
cations. For example when it goes
about shielding of computer housings,
some of the largest manufacurers in
the world are customers to Ensto.
According to the customers re-
quest, EMC shielding can be made
on metal as well on plastic enclosures,
with preservation of the adequate
degree of tightness.
Radio frequency interference (RFI)
and Elektromagnetic interfrence (EMI)
can be prevented from penetrating
or escaping from an enclosure by en-
suring it acts as a Farday Cage. This
means providing electrically
conductive shielding over all the
surfaces. Doors and ports have
to be electrically sealed to their
apertures. In practice this need not to
be continous provided the frequencies
being shielded cannot escape.
Ensto CUBO EMC offer solutions
using dual function gaskets that
both shield and retain a level of IP
rating but this is often less effective
than two separate gasket dedicated
to their own function.
The overall levels of attenuation vary
depended upon design, gasketing
used and maintenance.
The latter is very important as con-
taminants build up on the conductive
surfaces over a period of time so
reducing the conductive effect. This
is more common in designs with
“butt” joints. Gaskets sealing with
a wiping action offer a level of self
cleaning to retain their shielding
levels without maintenace for longer.
Shielding windows can be provided
by using material with a lamination
of conductive mesh but this will
need connecting to the door or
aperture continuously around its
edge.
In january 1996 the European Direc-
tive on Electromagnetic Compality
(EMC) came into force. This directive
demands that all products suscep-
tible to or capable of emitting EMI
must be designed so that their func-
tion is not unduly degraded in the
Ensto CUBO EMC enclosures