Demagnetization [degaussing]

The demagnetization is the process by which the magnetic charge is eliminated from an object, both of a ferrous metal nature and of another nature. Degaussing is the process of decreasing or eliminating a remnant magnetic field. It is named after the gauss, a unit of magnetism, which in turn was named after Carl Friedrich Gauss. Due to magnetic hysteresis, it is generally not possible to reduce a magnetic field completely to zero, so degaussing typically induces a very small “known” field referred to as bias. Degaussing was originally applied to reduce ships’ magnetic signatures during World War II.

Technically, degaussers activate a controlled and measurable magnetic field in Gauss. All media defined as “magnetic” such as hard disks and tapes have their own coercivity that is the intensity of the reverse magnetic field that must be applied to a material to cancel its magnetization, this is measured in Oersted (Oe). The Oersted value allows us to understand the degree of complexity about the cancellation of a media; in essence, the higher the Oe indicator, the stronger the power of the magnetic field that will have to be applied for the definitive deletion of the data.