How does a degausser work?

When it comes to secure and irreversible data destruction, there are two certified methods:

• Demagnetization with a degausser
• Mechanical destruction via shredding
• Incineration or melting of the device

These methods are highly effective, particularly when the storage media is defective or the necessary hardware to access the data is no longer available. However, it’s crucial to understand that once a degausser or shredder is used, the media becomes permanently unusable.

What Is Demagnetization?

Demagnetization is a powerful technique for permanently erasing data from magnetic storage media, including:

• Hard drives
• Floppy disks
• Magnetic tapes (open reels or cassette formats)
• Other magnetic media

This method is especially useful when hardware failures make traditional data overwriting software impractical or ineffective.

How Does Demagnetization Work?

The process is based on the polarization of Weiss domains—a principle discovered by French physicist Pierre Weiss.

The Science Behind It

Data stored on magnetic media—such as hard disks and tapes—is recorded by applying a magnetic field to tiny areas called magnetic domains (specifically Weiss domains).

During data writing, the magnetic field aligns the magnetization of these domains, encoding bit values of 0 and 1.

A degausser disrupts this process by applying an intense magnetic field that eliminates the alignment, thereby erasing all stored information. 

What Does Demagnetization Do to a Hard Drive?

A sufficiently strong magnetic field ensures complete and irreversible data erasure. However, not all degaussers are equally effective—especially with the most modern high-density hard drives and tapes.

To fully erase data, a degausser must counteract the coercive force of the storage medium.

• Coercive force is the strength of the reverse magnetic field needed to cancel the magnetization.
• For a degausser to be effective, it must generate a magnetic field at least 1.5 times stronger than the coercive force of the media being erased.

Key Considerations:

✔ Higher-powered degaussers offer greater effectiveness, ensuring compatibility with future storage technologies.

✔ The entire process takes only seconds—simply place the device in the tray and activate demagnetization.

✔ After demagnetization, the media is permanently unusable and can be recycled.

Which Storage Media Can Be Demagnetized?

A degausser is designed to erase data from all types of magnetic storage, including:

✅ Hard disk drives (5 ¼-inch, 3 ½-inch, and 2 1/2 -inch)

✅ Digital magnetic tapes (LTO, DLT, and other common formats)

✅ Floppy disks (5 ¼-inch and 3 ½-inch)

Learn More About Degaussing

At Ontrack, we offer a variety of data erasure solutions to ensure 100% secure destruction of your media.

Get in touch with our data erasure experts today to explore the best solutions for your needs.

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