Path: utzoo!utgpu!water!watmath!clyde!att!cuuxb!dlm From: dlm@cuuxb.ATT.COM (Dennis L. Mumaugh) Newsgroups: comp.misc Subject: Re: X-Ray detectors and Tapes Summary: X-rays don't normally hurt digital tapes Message-ID: <1925@cuuxb.ATT.COM> Date: 15 Jul 88 22:27:11 GMT References: <588@bnlux0.bnl.gov> Reply-To: dlm@cuuxb.UUCP (Dennis L. Mumaugh) Distribution: na Organization: ATT Data Systems Group, Lisle, Ill. Lines: 36 In article <588@bnlux0.bnl.gov> larese@bnlux0.UUCP (john z larese) writes: >I have just changed my place of work and I am now working in >a High security nuclear reactor. As employees, such as myself >enter the building, we pass all bags through a X-Ray detector >and walk through a metal detector. > >My question is, do any magnetic fields exist in either equipment >that might be high enough to damage Mag tapes? > In a time long ago ... NBS did a study and a report on the effects of magnetic fields on tapes. A short summary - locate the report for more: 1). Digital tapes are very difficult to erase. Audio tapes are easy as are video tapes. 2). Airport equipment will not normally erase a digital tape. 3). The old war story about a person walking into a computer room and erasing all the tapes or the one about the floor polished doing so is just that: a story, urban myths. 4). Their studies said that only a LARGE permanent magnet brought within 2 inches or the tape OR a special bulk eraser designed for digital tapes would erase it. BUT, it also cautioned about putting tapes near a disk drive with a large solenoid magnet or near the power supply of an X-ray machine. It also didn't address floppy disks. BTW it did discuss temperature and humidity, etc. as well. So check NTIS or NBS for the report. -- =Dennis L. Mumaugh Lisle, IL ...!{att,lll-crg}!cuuxb!dlm OR cuuxb!dlm@arpa.att.com