 - A Faraday cage is a metallic enclosure that prevents the entry or escape
of an electromagnetic field (EM field). An ideal Faraday cage consists
of an unbroken, perfectly conducting shell. This ideal cannot be achieved in
practice, but can be approached by using fine-mesh copper screening. For
best performance, the cage should be directly connected to an earth ground.
Faraday cages are used in electronic labs where stray EM fields must be
kept out. This is important in the testing of sensitive wireless receiving
equipment. In addition, a Faraday cage can prevent the escape of the EM
fields emitted by a cathode-ray-tube (CRT) computer monitor.
Such fields can be intercepted and translated to allow hackers to remotely
view on-screen data in real time without the need for wires, cables, or
cameras. This practice, known as van Eck phreaking, can also be
used by government officials to view the computer activities of known
criminals and certain criminal suspects.
A heavy-duty Faraday cage can protect against direct lightning strikes.
When properly connected to an earth ground, the cage conducts the high
current harmlessly to ground, and keeps the EM pulse from affecting
personnel or hardware inside.
| LAST UPDATED: |
21 Dec 2003
|
 |
Do you have something to add to this definition? Let us know.
Send your comments to techterms@whatis.com
|
|
More resources from around the web:
|
|
