EMF Shielding

EMF shielding is used by industry to shield against EMF or Electro-magnetic Fields which are created by electrical current travelling through substation transformers, switchrooms, switchboards and electrical cabling.

The EMF level is commonly express in units of millitesla (mT) or milligauss (mG), where 1 mT is equivalent to 10,000 mG.

Australian EMF exposure limits for 50 Hz magnetic fields are detailed in ARPANSA / NHMRC Radiation Health Series No. 30 (RHS30) and are detailed as follows:

Common industry practice is to use EMF shielding to restrict exposure to EMF fields to as low level as possible and an EMF level of 10 mG is often referenced, which is 100 times lower than the Australian EMF exposure limits (for 24 hour general public exposure).

EMF shielding installed around substations and electrical cabling will generally achieve a reduction in the EMF level to around 10 - 20 mG, which is considered to be as low as practically achievable for most commercial sites.

High permeability steel is used for EMF shielding of substations, switchrooms and cabling. Compliance Engineering Pty Ltd offer “M36 Shield” for EMF shielding applications, which can be purchased as individual sheets for installation by your own trades people. Alternately Compliance Engineering can supply and install the EMF shielding for you.

EMF shielding may also be used in residential applications behind the switchboard to reduce the EMF level occupants are exposed to. This is most commonly applied when a bedroom is located against the wall where the switchboard has been installed.

M36 Shield

High Permeability EMF Shielding Material

Typical uses of “M36 Shield” include EMF shielding of 50 Hz power frequency magnetic fields from substations, switchboards and associated electrical cabling.

“M36 Shield” is supplied in individual sheets measuring 1 m x 2.4 m x 0.5 mm. Typically 3 layers are required with the butt joints of each layer staggered away from the butt joint of the layer below.

The EMF shielding performance of “M36 Shield” will vary according to the intensity of the magnetic field it is subjected to (the higher the magnetic field the better the attenuation performance). 2 layers of “M36 Shield” are expected to provide a reduction to magnetic fields by a factor of 3 to 6 times (10 to 15 dB of attenuation), while each subsequent layer of “M36 Shield” will have diminishing attenuation performance (as the magnetic field intensity is reduced).

When magnetic fields encounter “M36 Shield”, the magnetic forces are both absorbed by and redirected away from its target. “M36 Shield” should be installed as close as possible to the magnetic field generating source and should extend out beyond the area where high (above the level required) magnetic field levels have been observed.

Fixing of “M36 Shield” is performed with the use of masonry anchors to concrete slabs, or screws into timber studs. “M36 Shield” can also be layered and fixed in place with contact adhesive onto bare floor surfaces prior to the application of carpet.

Compliance Engineering can provide and install EMF shielding around substations and electrical wiring in office, apartment and other commercial developments.

Compliance Engineering Pty Ltd
Unit 1, 70 Rushdale Street
Knoxfield VIC 3180 Australia
Telephone: + 61 3 9763 3079
Facsimile: + 61 3 9763 9706
Email: info@compeng.com.au
Web: www.compeng.com.au
ABN: 56 101 639 588

Visit our main website for more details on the complete range of services offered by Compliance Engineering: www.compeng.com.au