Editing Data remanence (section)

===Degaussing===

[[Bulk eraser|Degaussing]] is the removal or reduction of a magnetic field of a disk or drive, using a device called a degausser that has been designed for the media being erased. Applied to [[magnetic storage|magnetic media]], degaussing may purge an entire media element quickly and effectively.

Degaussing often renders [[hard disk]]s inoperable, as it erases low-level [[disk format|formatting]] that is only done at the factory during manufacturing. In some cases, it is possible to return the drive to a functional state by having it serviced at the manufacturer. However, some modern degaussers use such a strong magnetic pulse that the motor that spins the platters may be destroyed in the degaussing process, and servicing may not be cost-effective. Degaussed computer tape such as [[Digital Linear Tape|DLT]] can generally be reformatted and reused with standard consumer hardware.

In some high-security environments, one may be required to use a degausser that has been approved for the task. For example, in [[United States|US]] government and military jurisdictions, one may be required to use a degausser from the [[National Security Agency|NSA]]'s "Evaluated Products List".<ref name="NSAEPL">{{cite web
 | title=Media Destruction Guidance
 | publisher=NSA
 | url=http://www.nsa.gov/ia/mitigation_guidance/media_destruction_guidance/
 | access-date=2009-03-01
 | archive-date=2012-09-28
 | archive-url=https://web.archive.org/web/20120928000816/https://www.nsa.gov/ia/mitigation_guidance/media_destruction_guidance/
 | url-status=dead
 }}</ref>