A magnetic recording tape layer-to-layer adhesion tester
Test apparatus for evaluating magnetic tape interlayer adhesion problem
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Test apparatus for evaluating magnetic tape interlayer adhesion problem
This document establishes the same kinds of standards and controls that are currently in use for the procurement on new analog and digital magnetic tapes. The Magnetic Tape Certification Facility (MTCF) currently maintains a Quality Products List (QPL) for all new analog and digital magnetic tapes purchased by NASA-GSFC. Extensive tests are conducted in the MTCF on an annual basis to determine the manufacturer's tape types to be added to or deleted from the current QPL. The MTCF currently maintains two specifications for magnetic tapes: NASA TM-79724 is used for the QPL and acceptance testing of new analog tapes; and NASA TM-80599 is used for the QPL and acceptance testing of new digital tapes. This specification will be used for the QPL and acceptance testing of new 3480 cartridges. The magnetic tapes used by GSFC, LaRC, ARC/Dryden, WFF, and the Network Tracking Stations are covered by the NASA-GSFC specifications. The 3480 cartridge was introduced approximately 3.5 years ago and is becoming an increasingly attractive alternative to digital magnetic tapes. Many users have already converted to the 3480 system and have more tape drives on order.
During the 1970's, a commercial magnetic recording tape fabricated with magnetic oxide particles, and with oxide and backcoat binders made from polyester urethane was being used for spacecraft tape recorders, and which would periodically manifest operational problems such as layer-to-layer adhesion, stick-slip, and shedding of sticky organic materials. These problems were generally associated with periods of high humidity. An experimental study identified that these problems resulted from hydrolysis of the polyester urethane binders.
Methods were developed to determine the coefficient of friction and the extent of stick-slip of magnetic recording tapes. After a preliminary phase during which experimental procedures were established and screening of candidate tapes was carried out, the frictional and stick-slip behavior of four selected tapes, using four different kinds of magnetic heads, was studied at various temperatures, under dry and humid conditions, and in various gaseous atmospheres, such as argon, helium, nitrogen and air. The effects of tape speed and outgassing on the drag properties of the tapes were also studied. A rank was assigned to each tape and magnetic head as a result of these tests. This study helped in the selection of a magnetic tape in a flight project, and will be useful in the consideration of tapes and magnetic heads for future spacecraft applications.
The kinetics of the hydrolysis of polyester urethane binders of magnetic recording tape is described. Kinetic data were generated from measurements of acetone-extractable hydrolyzed binder products versus time for various humidity-temperature environments. These data can be described by a linear, single product, reversible rate equation. This equation, coupled with measurements on the effect of hydrolysis on recorded tape performance, is used to predict proper environmental storage conditions for magnetic tape.
Methods were developed for measuring frictional forces acting on a magnetic tape in motion or at rest, as well as the extent of stick slip. The effects of factors such as temperature, humidity, kind of gaseous atmosphere, and tape speed on the frictional interaction between various tapes and heads were investigated. Results were instrumental in the selection of a tape for the Mariner Mars 1971 spacecraft. Studies are reported on the stick slip behavior of tapes and the performance of a metallic tape, compared with the usual plastic tapes.
Causes of signal loss in magnetic computer tapes, and wet and dry cleaning procedures for rehabilitating used tapes
The design requirements are given for magnetic oxide coated, electronic data processing tape, wound on reels. Magnetic recording tape types covered by this specification are intended for use on digital tape transports using the Non-Return-to-Zero-change-on-ones (NRZI) recording method for recording densities up to and including 800 characters per inch (cpi) and the Phase-Encoding (PE) recording method for a recording density of 1600 cpi.
Scanner for short sections of magnetic recording tape
Development of low friction magnetic recording tape
Ephemeris magnetic tape system for predicting Moon and planetary motions and positions
The same kind of standard and controls are established that are currently in use for the procurement of new analog, digital, and IBM/IBM compatible 3480 tape cartridges, and 1 in wide channel video magnetic tapes. The Magnetic Tape Certification Facility (MTCF) maintains a Qualified Products List (QPL) for the procurement of new magnetic media and uses the following specifications for the QPL and Acceptance Tests: (1) NASA TM-79724 is used for the QPL and Acceptance Testing of new analog magnetic tapes; (2) NASA TM-80599 is used for the QPL and Acceptance Testing of new digital magnetic tapes; (3) NASA TM-100702 is used for the QPL and Acceptance Testing of new IBM/IBM compatible 3840 magnetic tape cartridges; and (4) NASA TM-100712 is used for the QPL and Acceptance Testing of new 1 in wide channel video magnetic tapes. This document will be used for the QPL and Acceptance Testing of new Helical Scan 8 mm digital data tape cartridges.
Standards for removable computer storage media are needed so that users may reliably interchange data both within and among various computer installations. Furthermore, media interchange standards support competition in industry and prevent sole-source lock-in. NIST participates in magnetic tape and optical disk standards development through Technical Committees X3B5, Digital Magnetic Tapes, X3B11, Optical Digital Data Disk, and the Joint Technical Commission on Data Permanence. NIST also participates in other relevant national and international standards committees for removable computer storage media. Industry standards for digital magnetic tapes require the use of Standard Reference Materials (SRM's) developed and maintained by NIST. In addition, NIST has been studying care and handling procedures required for digital magnetic tapes. NIST has developed a methodology for determining the life expectancy of optical disks. NIST is developing care and handling procedures for optical digital data disks and is involved in a program to investigate error reporting capabilities of optical disk drives. This presentation reflects the status of emerging magnetic tape and optical disk standards, as well as NIST's contributions in support of these standards.
The catalog contains the observational results obtained by the Celescope Experiment during the first 16 months of operation of NASA's Orbiting Astronomical Observatory (OAO-2). It lists the results of the stellar observations, along with selected ground-based information obtained from the available literature. Lunar observations (Ahmad and Deutschman, 1972), as well as other analyses of the data, are being published as separate papers. These data are available in two forms: (1) magnetic tapes and the necessary utility programs for reading and printing the contents of the tapes; and (2) this catalog, transcribed from the magnetic-tape catalog. The magnetic tape version contains not only the compiled results but also the results of the individual observations from which these averaged data were compiled.
Disturbances created by certain assemblies and components of tape-feed mechanisms (TFM) and acting on a moving magnetic tape are studied. The method, based on elements of digital logic, is established by stress-strain diagrams of the longitudinal deformations and vibrations across the width of a magnetic tape. Experimental studies were carried out for determination of the functional relationships of longitudinal deformations in a section of magnetic tape to the magnitude of roller play, tension vibrations rate of movement, and elasticity of magnetic tapes. A block diagram of the measurements is shown. Appropriate digital computer algorithms and programs were proposed for statistical analysis of the data obtained. Estimates of the mathematical expectation, dispersion, intercorrelation function, energy spectral density, and distribution pattern of the random process values were calculated.
Relative humidity has been recognized as an important environmental factor in many head-tape interface phenomena such as headwear, friction, staining, and tape shed. Accordingly, the relative humidity is usually specified in many applications of tape use, especially when tape recorders are enclosed in hermetically sealed cases. Normally, the relative humidity is believed regulated by humidification of the fill gas to the specification relative humidity. This study demonstrates that the internal relative humidity in a sealed case is completely controlled by the time-dpendence of the hygroscopic properties of the pack of magnetic recording tape. Differences are found in the hygroscopic properties of the same brand of tape, which apparently result from aging, and which may have an effect on the long-term humidity-regulating behavior in a sealed case, and on the occurrence of head-tape interface phenomena from the long-term use of the tape. Results are presented on the basic hygroscopic properties of magnetic tape, its humidity-regulating behavior in a sealed case, and a theoretical commentary on the relative humidity dependence of head-wear by tape, is included.
Kinetic and static friction force measurement between magnetic tape and magnetic head surfaces
Preliminary stages in the design, construction, and development of a photoelectric photometer system interfaced with an IMSAI 8080 microcomputer. The instrument will also include magnetic tape and magnetic disk storage capabilities to enable rapid data storage. The capability of the instrument to make observations with very high time resolution, as high as 10 msec, and measure the intensity and polarization of radiation emitted by objects which show very rapid light variations, pulsars and optical counterparts of X-ray sources was of concern. A better understanding of the magnetic fields and interstellar material which characterize the immediate environment of these stellar systems and an expansion of the observational capabilities of even modest-sized telescopes are expected.