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Testing Magnetic Recording Tape

IP.com Disclosure Number: IPCOM000095267D
Original Publication Date: 1965-Nov-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Klaas, EC: AUTHOR [+2]

Abstract

Procedures and apparatus for testing magnetic recording tape are simplified by this method. Testing for use at all possible recording densities is performed by testing at the highest density only. Defect dropouts on a magnetic recording tape are primarily caused by particles or irregularities on the tape surface. A particle of given size on a tape with information recorded at one density causes the amplitude of a number of successive detected signals to drop below a predetermined level. The same particle causes a signal amplitude reduction below a second level for a different number of detected signals at another recording density.

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Testing Magnetic Recording Tape

Procedures and apparatus for testing magnetic recording tape are simplified by this method. Testing for use at all possible recording densities is performed by testing at the highest density only. Defect dropouts on a magnetic recording tape are primarily caused by particles or irregularities on the tape surface. A particle of given size on a tape with information recorded at one density causes the amplitude of a number of successive detected signals to drop below a predetermined level. The same particle causes a signal amplitude reduction below a second level for a different number of detected signals at another recording density.

Recording tape is currently tested at each possible recording density for defect dropouts. The number of allowable defects is known for each recording density. Thus, the determination is made as to the availability of a particular recording tape for use at a particular density. With the increase in frequency of recording and the number of such frequencies, these procedures and the apparatus required for testing the tape have become more numerous.

This method predetermines the number of permissible defects for each recording density as related to the single test density. The tape is then tested at this single density. The number of defects is determined by measuring the number of successive signals falling below predetermined amplitude levels. To illustrate, rather than test tape at three recording densit...