Datashield can supply a range of degaussers suitable for today’s high coercivity tapes such as Super DLT and LTO as well as Hard Disk.
Don’t be lulled into purchasing a toy which is not up to the job. The Verity V91 and V92 Degaussers are specifically designed with a high Gauss rating of approximately 4000 which is demanded to ensure complete erasure of your data, or just to make your DLTIV tapes work in the newer DLT1 drives.
The above degaussers start at $3800 plus Freight and GST. (subject to Exchange Rate Fluctuations)
Why would anyone want to degauss magnetic media
in the first place?
For starters, we degauss media:
Today's records relative to insurance, consumer credit, bank records, etc., all must meet various standards of data privacy. How about national defense?
So, degaussing makes sense. But, you say, "I don't know anything about degaussing." Don't be alarmed--you've got a lot of company!
First of all, degaussing is merely a fast, efficient way of removing all audio, video, and data signals from magnetic tape.
Incidentally, IBM has published information on degaussing. Chapter 1, page 3 of the Care and Handling of the IBM Magnetic Cartridge states "AC erasing all the magnetic records from tape for security reasons will not damage the tape."
However, there are a couple of exceptions that are mentioned at the end of this article.
Let's suppose that you have a cartridge or reel of magnetic tape that is already encoded and you want to dispose of it. OK, we'll degauss it.
A long time ago, someone developed this thing called a degausser. The early versions were crude by today's standards and looked something like a hot plate. Confidentiality in those days, wasn't as critical as it is today. Times have changed and we are concerned that sensitive information might fall into the wrong hands.
So, how's it done?
Basically, all you do is introduce the recorded magnetic tape into a very strong magnetic field and uniformly withdraw it from this same magnetic field. As it is leaving the magnetic field, the magnetization of the recorded data becomes weaker and weaker until there is no residual magnetic signals remaining on the media. In other words, you put it in (magnetize it) and you take it out (demagnetize it)!
"Oh, yeah, I'll bet there is lot more to it than that." You can bet there is! There have been books written about it but since you don't intend to make it a lifetime study, we'll keep it simple. Don't try to get too technical.
Some media is harder to degauss than others. For example, a 3420 reel-to-reel tape at 320 oersteds is easier to degauss that a cartridge at 1800 oersteds. In fact, most cartridges being used today have a high coercivity rating--most around 1800 oersteds, but also much higher.
All this means is that you should choose a degausser depending on the coercivity rating of the cartridge to be degaussed. A degausser designed to degauss media with a maximum coercivity rating of 320 oersteds will not properly degauss media at the 2400 oersted rating.
Coercivity is a measure, in oersteds, of the magnetizability or erasability of a tape or cartridge.
The higher the coercivity number: the more energy needed to degauss it.
The higher the coercivity: the harder to erase.
Datashield degausses tapes using a V91 machine with the correct oersted rating.
© Datashield 2005