The procedure of weakening a magnetic field is known as degaussing. It can be used to erase the data from a magnetic recording device or to restore the magnetic field of a CRT display.

A cathode ray tube (CRT) is used in CRT monitors to project pictures onto the screen. The shadow shield, a disk close to the screen, focuses the electron rays. The screen may become discolored if this plate is irregularly attracted by nearby items or just the magnetic field of the planet. As a result, "Degauss" commands are frequently found on CRT displays, which when used, restore the magnetic field. Since the magnetic charge inside the monitor cannot be completely removed, the degaussing procedure realigns or randomizes the magnetic field, which produces uniform hues throughout the display.

Data on a magnetic recording device, like a hard drive or cassette drive, can also be erased using degaussing. For instance, a hard drive degausser has a compartment into which you can put a hard drive. The degausser reduces the magnetic field of the drive through a procedure known as capacitative discharge, rendering all data on the drive useless. The time it takes for the data to be deleted, known as the cycle time, differs between degaussers but is typically between ten seconds and one minute. Degaussers can be used by businesses and government agencies to erase data from storage devices before they are replaced or thrown away.