An alternating current (AC) bulk eraser (degausser) is used for complete erasure of data and other signals on magnetic media. Degaussing is a process where magnetic media is exposed to a powerful, alternating magnetic field. Degaussing removes any previously written data, leaving the media in a magnetically randomized (blank) state.

The degausser must subject the media to an alternating magnetic field of sufficient intensity to saturate the media and then by slowly withdrawing or reducing the field, the magnetic media is left in a magnetically neutral state.

To erase recorded data, it is necessary for the strength of the degaussing field to be greater in value than the coercivity of the magnetic media. Simply stated, coercivity is the magnetic field strength, rated in oersteds (Oe), required to change the magnetic orientation of the magnetic material. Check with knowledgeable dealers or degausser manufacturers to identify degausser models that meet your requirements.

Data is typically not lost until its level has been decreased 65% to 75% (or more) below its original saturation recording signal level, dependent upon the drive system.

 

For more information on erase hard drive computer, erasing hard drives, degaussing equipment, and degaussing services, see also: per-1100 disk degausser delete data tracker wipe hard drive clean software pc hard drive cleaning hd-1 audio tape degausser per-1100 drive eraser per-1100 drive eraser mds-4 tape degausser degauss camcorder disk eraser free windows xp delete unnecessary files second hard drive per-4516 tape eraser per-1100 diskette eraser used computers v-890 video tape degausser degauser make clean your hard drive whole-house media air cleaners erase hard drive computer v-880 tape degausser navy degausing system product v92 eraser how to erase files from hard drive v-880 tape eraser steps for cleaning data in a data warehouse cds 2500a feed hopper tape degausser per-1100 drive degausser unix admin and wipe disk and erase all erase hard drive utility v-860 eraser cds 2500a feed hopper degausser td1b tape degausser c64 disk erase how to erase the hard drive what files are safe to delete from my hard drive automatically erase file after reading per-4516 tape eraser v-860 gsa schedule per-1100 hard drive eraser pc hard drive cleaning

A complete erasure level, for most users, is considered to be 60 dB below the original signal level – this of course depends on user requirements. A 60 dB signal decrease equates to reducing the signal to one tenth of one percent of its original value.

Magnetic media products that have factory prerecorded magnetic servo patterns should not be degaussed. Degaussing would erase the factory written magnetic servo signals and leave the media unusable. For all other magnetic media (without magnetic servo signals), after proper degaussing, the quality of subsequent data recording should be unchanged or even improved.

It is very important to understand and follow the degausser’s operating instructions. This is especially important for manual units where the operator controls the media’s movement through the degaussing field. For higher coercivity media, four passes are often recommended – two passes, with a 90 degree rotation for the second pass, and then repeat the process with the media turned upside-down. Of course, these and other important operating considerations will vary with the type, power and construction of the individual degausser models.

For more information on erase hard drive computer, degaussers, erasing hard drives, cleaning hard drives, degaussing, and erasing harddrives, see also: