What does demagnetiser mean?
Demagnetiser is a device used to remove residual magnetisation from another object. The term is especially common in electronics, audio maintenance and data recovery, where magnetic fields can interfere with sensitive components or erase recorded information. Rather than simply placing a permanent magnet nearby, a demagnetiser commonly applies an alternating or changing magnetic field that reduces the object's retained alignment. The word is a technical noun used almost entirely for apparatus. In British English the -iser spelling is standard, while the American form is demagnetizer. The related verb demagnetise means “to remove magnetisation,” and demagnetisation names that process. The term is useful because residual magnetisation is invisible but can produce practical problems in recording, servicing and precision work.
nounA demagnetiser is a device that removes or reduces residual magnetisation from an object. It commonly uses an alternating or changing magnetic field to cancel unwanted magnetic alignment.
- A device or apparatus that removes or reduces magnetisation from an object.
"The technician used a demagnetiser to clear residual magnetism from the tape heads."
"Use a demagnetiser to clear residual magnetism from the tape heads."
"A demagnetiser was used to neutralise the magnetised sensor before calibration."
The standard plural adds -s to the noun.
"The workshop keeps several small demagnetisers on hand."
A demagnetiser is magnetic undo: it uses a changing field to help cancel magnetisation that a permanent magnet would otherwise leave behind.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of demagnetiser
Demagnetiser was formed in English by combining de-, meaning removal or reversal, with magnet and the suffix -iser; the additional -er identifies a device that performs the action. The root magnet ultimately derives from Greek magnētis, a term associated with the lodestone. The American spelling demagnetizer reflects the same formation with the usual -izer ending.
Related word forms
How demagnetiser is actually used
This is primarily a technical term for equipment. It is less common in general conversation and normally denotes a device rather than a person.
Easily confused with demagnetiser
Demagnetiser is the usual British spelling, while demagnetizer is the standard American spelling of the same word.
A degausser is a specialised electromagnetic device, often used to erase data from magnetic recording media, whereas a demagnetiser is the more general term for equipment that removes magnetisation.