If you plan to travel by plane, you're probably worried about whether your valuable recordings made on tapes or discs will survive inspection by airport authorities. By virtue of the installation of even more powerful scanning equipment, thanks to the courtesy of the jumbo jet nihilists among us, this concern is even greater.
Can these new and improved devices erase your data or are you unnecessarily worried? While the possibility of erasure is remote, there are reasons to be careful, especially if you transport old belt formats or floppy disks.
Cargo baggage or carry-on baggage?
In accordance with the new guidelines issued by the Transportation Security Administration, TSA, of the United States, all cargo baggage must be passed through the screen in advance of boarding.
During the scanning process, cargo baggage can pass through three types of scanner, including X-ray equipment and two different explosive detection systems. Even so, it is doubtful that these systems will have any negative impact on data recorded on magnetic media. In fact, the TSA states that "none of the scanning equipment ... it affects images from digital cameras or already processed footage, slides, videos, photography compact discs or image discs."
However, the biggest concern about the media contained in cargo baggage is not electronic damage, but its physical loss. Airport staff have the authority (and obligation) to open and inspect any suspicious pieces of baggage, including those that are locked (suggestion: lock your luggage without a key); however, baggage beyond your control is subject to increased risk of damage, loss and even theft. Therefore, you must carry in your hand luggage your tapes, discs and other valuables.
Passenger inspection points: fixed and handheld metal detectors, X-rays
Right, he has decided to take his tapes with him. Even so, they have to go through similar scanning systems. Is it possible for these systems to cause data corruption? In order to know this, it is necessary to understand how magnetic media are recorded.
The data is recorded on tapes and discs ordering metal particles using a powerful magnetic field. In the case of tapes, the magnetic energy is supplied by the recording headbutt, which makes direct contact with the tape. In the case of discs, the recording head floats just above the surface. Both methods deliver an enormous amount of magnetic energy, very close to the media within a very confined area.
Disorganizing carefully ordered magnetic particles from a distance requires a tremendous amount of magnetic energy. How much energy is required depends on the distance and the coercive factor of the media, that is, the magnetic force required to "force" the point of zero magnetism.
Floppy floppy disks have a low coercivity factor. In other words, it doesn't take much magnetic energy to mess them up. The same can be said for non-metallic audio tapes, older format videotapes in metal oxide media such as 3/4 inch, VHS, and 8mm, all of which have low coercivity factors. At the opposite end of the scale are modern tape formats that employ pure metal particles or pure vaporized metal formulas. These tapes, which include DVCAM, MiniDV, Hi8 and Betacam SP, feature very high coercivity factors and high erasure resistance.
X-rays are not magnetic and obviously do not cause problems on their own. Many guesses about the spurious magnetic energy produced by X-ray equipment and most conveyor belt motors can cause concern. However, to date, no damage caused by these sources has been documented.
Direct sources of magnetic energy are in arc metal detectors and handheld metal detectors. While it is doubtful that any of these devices can cause damage, some handheld metal detectors, in theory, generate enough magnetic energy to damage data stored in low-coercive formats. Our practical experience, however, has not confirmed this.
Films
Unlike magnetic media, X-rays will most likely ruin undeveloped films. The TSA states that films under the 800 ASA/ISO standard will not be affected by passenger inspection X-ray equipment, but also states that the cumulative effect of several passes through these devices can cloud even low-speed films.
Conclusion
According to the TSA and user and manufacturer reports, in addition to our own personal experiences, it is unlikely that any of the current scanning devices can corrupt data recorded on magnetic media. On the other hand, the greatest source of problems is attributed to damage or loss due to manual inspection of cargo baggage.
If you are still concerned about the effect of passenger inspection scanner equipment, you can always ask inspectors to check your luggage by hand. It may take a little longer, but this hassle is offset by the relief of knowing your data is safe.
Copyright 2004, Electric Picture Company, Inc.
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