What is degaussing and what are the benefits and drawbacks?
An extensive explanation of “what is degaussing,” how it operates, types of degaussers, types of media degaussing supports, etc., are provided in this page. It also aids in comprehending degaussing’s alternatives and the reasons behind its avoidance or restricted use in data destruction strategies by firms.
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Degaussing: What Is It?
Degaussing is a method of destroying data that involves demagnetizing or neutralizing the magnetic field that is used to store data on magnetic media, including floppies and hard drives.
The magnetic storage medium may be seen as a big “magnetized surface” that has been divided into several tiny sub-micron magnetic patches by a powerful local magnetic field produced by a media writing head. The data is stored in these magnetic domains, which have uniform and local field orientations of their own. By neutralizing the field orientations of these discrete magnetic domains, the degaussing procedure destroys the data.
How Does Degaussing Occur?
Using a degausser machine, which employs a high magnetic field to rearrange or randomize the magnetized domains on the storage media’s existing polarity (orientation), degaussing is carried out. This leads to the primary destruction of the data stored on these magnetic domains. Nevertheless, a degausser’s effectiveness is dependent on how strong its magnetic field is in relation to the medium it is degaussing.
To properly degauss magnetic material, the degausser’s coercivity has to be 2-3 times that of the media. The magnetic material’s resistance to changes in the direction of its magnetic field is known as coercivity, and it is expressed in oersted units. Due to this feature, degaussing medium with a greater coercivity will be more difficult and require more powerful equipment. The emerging magnetic media with cutting-edge recording technologies have increased coercivities, according NIST SP 800-88 criteria. Because of this, current degaussers might not be strong enough to completely sterilize them.
Furthermore, for degaussing to be effective, the power of the degausser and the medium coercivity must be precisely matched. Reaching these requirements might be a technological challenge. NIST SP 800-88 Guidelines state that “when the strength of the degausser is carefully matched to the media coercivity, degaussing renders a legacy magnetic device purged.” Determining coercivity just from the information on the label may prove to be challenging.”
Different kinds of degaussers
Based on the method by which they produce the magnetic field, degaussers or degaussing devices can be broadly classified into three categories:
Degausser coil:
A steel core is wrapped with copper wire to create the coil degausser. When the setup is powered by an alternating current, a powerful electromagnetic field is generated. Hard drives and other magnetic storage devices are demagnetized using this electromagnetic field.
Degausser with Capacitive Discharge:
In order to demagnetize the storage medium, this degaussing device stores electrical charge in a capacitor and discharges the energy as a powerful high-frequency electromagnetic pulse. The data is destroyed when the magnetic storage medium is degaussed by this technique. Another name for the capacitive discharge degausser is the pulse degausser.
Degausser with permanent magnet:
These are naturally occurring rare-earth magnets with incredibly high field strengths, like neodymium magnets. To degauss magnetic media like hard drives, cassettes, etc., a permanent magnet is put in a certain configuration. The permanent magnet degausser doesn’t require an electrical charge, in contrast to coil or pulse degaussers.