Common Degausser Misconceptions and Myths
Learning what degaussing means is one thing. Congrats if this is you – it’s a complex topic! Debunking the common myths around degaussers, however, is quite another thing. So we’ve rounded up the most frequent rumors we’ve heard in our 37+ years in the industry. We hope this helps you make an informed decision before you buy.
5 common myths about degaussers:
- All degaussers are created equally
- All degaussers erase disk drives
- Formatting, deleting, and/or overwriting media is an adequate substitution for degaussing
- All electromagnetic degaussers create a dangerous magnetic field that escapes the degausser
- All electromagnetic degaussers heat media
Myth: All degaussers are created equally. Fact: There are many degaussers out there. Each is rated for different media based upon the degausser field strength. Magnetic field strength is measured in Gauss or Oersteds. Likewise, magnetic media has a property called coercivity. This is also measured in Oersteds, which tell you how hard or easy each tape or hard drive is to erase. To completely erase, a degausser’s magnetic field strength should be about 2 times the coercivity of the media. Today’s 5,000 Oersted hard disk drive need a magnetic field of at least 10,000 Gauss (Oersted); the greater the field, the better! 
Myth: All degaussers erase disk drives. Fact: Some degausser specifications claim a magnetic field strength of 4,000 Gauss (Oersted) or less. Unfortunately, most disk drives have coercivity ratings of 5,000 Oersteds. These degaussers are a far cry from being 2 times stronger than the coercivity of the media. If you want the information completely erased, check the degausser’s magnetic field strength before buying.
Myth: Formatting, deleting, and/or overwriting media is an adequate substitution for degaussing. Fact: Formatting, deleting, overwriting, Secure Erase and DoD Wipe do not eradicate all the data. These methods often simply remove pointers and compress disk space. The files themselves remain and can be recovered, leaving your data at risk. There is only one way to ensure all information is removed from a tape or disk. Use a degausser that’s listed in the National Security Agency’s Evaluated Products List for Magnetic Degaussers.
Myth: All electromagnetic degaussers create a dangerous magnetic field that escapes the degausser. Fact: At Data Security, Inc.®, we design our degaussers to shield the magnetic field inside the machine. We believe that a stray field is wasted energy. The magnetic field outside of a Data Security, Inc. ® degausser is equal to or less than the earth’s magnetic field.
Myth: All electromagnetic degaussers heat media. Fact: All electromagnetic degaussers do not heat media. When magnetic media encased in aluminum is exposed to an AC magnetic field for an extended period of time, the temperature of the media will rise. This is true of many commercial tabletop-style degaussers. A capacitive discharge degausser from Data Security, Inc. ® eliminates the constant exposure to an AC field and does not heat the media.
If you’d like to learn more about degaussers, contact Data Security, Inc.® at 1(800) 225-7554; we’ll help you find the right product to fit your needs.
Originally published December 3, 2024