ISO/IEC 13421:1993
(Main)Information technology — Data Interchange on 12,7 mm, 48-track magnetic tape cartridges — DLT 1 format
Information technology — Data Interchange on 12,7 mm, 48-track magnetic tape cartridges — DLT 1 format
La présente Norme internationale spécifie les caractéristiques physiques et magnétiques d'une cartouche à bande magnétique de 12,7 mm de large, 48 pistes, dans le but de permettre l'interchangeabilité de telles cartouches. Elle spécifie également la qualité des signaux enregistrés, un format appelé Bande Linéaire Numérique 1 (DLT1) et une méthode d'enregistrement. Associée à une norme d'étiquetage, comme par exemple la Norme internationale ISO 1001 pour la structure de volumes et de fichiers des bandes magnétiques, elle permet un échange total de données au moyen de telles cartouches à bande magnétique.
Technologies de l'information — Échange de données sur cartouches pour bandes magnétiques de 12,7 mm, 48 pistes — Format DLT 1
General Information
Standards Content (Sample)
INTERNATIONAL
ISOJIEC
STANDARD 13421
First edition
1993-12-15
Information technology - Data
interchange on 12,7 mm, 48-track magnetic
tape cartridges - DLT 1 format
Technologies de I’informa tion - khange de donndes SW cartouches
pour bandes magnetiques de 12,7 mm, 48 pistes - Format DLT 1
Reference number
ISO/IEC 13421 :1993(E)
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ISO/IEC 13421:1993 (E)
Contents
Page
1
Section 1 - General
1
1 Scope
1
Conformance
2
2.1 Magnetit tape cartridges
2.2 Generating Systems
Receiving Systems
23 .
1
3 References
1
4 Definitions
2
41 Average Signal Amplitude
2
4:2 azimuth
2
back surface
4.3
2
44 . Beginning-Of-Tape marker (BOT)
2
45 . byte
2
46 . cartridge
2
Cyclic Redundancy Check (CRC) Character
47
2
4:8 Early Warning (EW)
2
Error-Detecting Code (EDC)
49
2
4:10 End-Of-Tape marker (EOT)
2
4.11 Entity
2
4.12 Error-Correcting Code (ECC)
2
flux transition Position
4.13
2
4.14 flux transition spacing
2
4.15 Logical Block
2
logical track
4.16
2
4.17 magnetic tape
3
4.18 Master Standard Reference Tape
0 TSO/IEC 1993
All rights reserved. No part of this publication may be reproduced or utilized in any form
or by any means, electronie or mechanical, including photocopying and microfilm,
without Permission in writing from the publisher.
ISO/IEC Copyright Office l Case postale 56 l CH-121 1 Geneve 20 l Switzerland
Printed in Switzerland
ii
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ISO/IEC 13421:1993 (E)
4.19 Object
physical block
4.20
physical recording density
4.21
4,22 physical track
4.23 Record
Reference Edge
4.24
4.25 Reference Field
4.26 Secondary Standard Reference Tape
Standard Reference Amplitude (SRA)
4.27
4.28 Standard Reference Current
4.29 Test Recording Current
4.30 Typical Field
Conventions and notations
5
3
5.1 Representation of numbers
4
52 Names
4
5:3 Acronyms
6 Environment and safety
6.1 Cartridge and tape testing environment
. Cartridge operating environment
62
. Cartridge storage environment
63
Safety requirements
64 .
6.4.1 Safeness
6.4.2 Flammability
5
65 . Transportation
5
Section 2 - Requirements for the unrecorded tape
7 Mechanical and electrical requirements
7.1 Material
7.2 Tape length
7.3 Width of the tape
7.4 Total thickness of the tape
7.5 Thickness of the base material
7.6 Thickness of the magnetic coating
7.7 Thickness of the back coating
7.8 Tape discontinuity
Longitudinal curvature
7.9
6
7.9.1 Requirement
6
7.9.2 Procedure
6
Out-of-Plane distortions
7.10
6
7.11 Cupping
7
7.12 Roughness of the coating surfaces
. . .
111
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ISO/IEC 13421:1993 (E)
7
Roughness of the back coating surface
7.12.1
7
7.12.2 Roughness of the magnetic coating surface
7
7.13 Coating adhesion
8
Layer-to-layer adhesion
7.14
7.14.1 Requirements
7.14.2 Procedure
Modulus of elasticity
7.15
Requirement
7.151
7el5.2 Procedure
Flexural rigidity
equirement
Procedure
Tensile yield forte
737.2 Procedure
Efectrical resistance
1
RtXpire-iilent
1
Rocedure
7.19 Inhibitor tape
7.20 Abrasivity
11
7.20.1 Requirement
11
Procedure
7.20.2
12
7.21 Light transmittance of the tape and the leader
12
7.22 Coefficient of dynamic friction
12
7.22.1 Requirements
12
Procedure for the measurement of the friction between the magnetic surface and the back surface
7.22.2
7.22.3 Procedure for the measurement of the friction between the magnetic surface or the back surface and
13
Calcium titanate ceramic
13
8 Magnetit recording characteristics
13
81 . Typical Field
14
82 . Signal amplitude
14
83 . Resolution
14
.
84 Overwrite
14
8.4.1 Requirement
14
85 . Peak shift
iv
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ISO/IEC 13421:1993 (E)
14
8.5.1 Requirement
14
8.5.2 Procedure
15
9 Tape quality
15
Missing pulses
91 .
15
9.1.1 Requirement
15
issing pulse Zone
9.2
equirement
93 6) Tape durability
General
Bottom side and right side
Back side and Ieft side
Tape reel
Tape Header
Front side
Operation of the cartridge
30
Section 4 - Requisements for an interchanged tape
30
Method of recording
11
30
11.1 Physical recording density
30
11.2 Bit cell length
30
Average bit cell length
11.2.1
30
11.2.2 Long-term average bit cell length
30
Short-term average bit cell length
11.2.3
30
11.3 Flux transition spacing
30
11.4 Read Signal amplitude
30
Azimuth
11.5
31
11.6 Channel skew
31
12 Tape format
31
12.1 Reference Edge
31
12.2 Direction of recording
31
12.3 Tape layout
32
12.4 Calibration and Directory Area
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ISO/IEC 13421:1993 (E)
32
12.4.1 Scratch Area
32
12.4.2 Guard Area Gl
32
12.4.3 Calibration Tracks Area
34
12.4.4 Guard Area G2
34
12.45 Directory Area
34
12.4.6 Guard Area G3
34
12.5 Data Area
34
12.5.1 Physical tracks
34
12.52 Width of the physical tracks
34
12.5.3 Logical tracks
34
12.5.4 Locations of the physical tracks
37
12.55 Layout of tracks in the Data Area
38
13 Data format
38
13.1 Data Bytes
38
13.2 Logical Blocks
38
13.3 Data Blocks
39
13.4 Types of Logical Blocks
39
13.5 Entities
39
13.6 Logical Block format
40
Preamble
13.6.1
40
13.6.2 Sync
40
13.6.3 Data Field
41
13.6.4 Control Field 1 (CFl)
43
13.6.5 Control Field 2 (CF2)
44
CRC
13.6.6
44
13.6.7 Postamble
44
14 Use of Logical Blocks
44
14.1 Data Blocks
44
Tape Mark Blocks
14.2
44
Filler Blocks
14.3
45
14.4 , End of Track Blocks (EOTR)
45
14.5 End of Data Blocks (EOD)
45
14.6 ECC Blocks
45
Format of Entities
15
45
16 Error handling
Annexes
47
A - Measurement of light transmittance
50
B - CRC generation
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ISO/IEC 13421:1993 (E)
C - ECC generation
51
D - Format of Control Field
54
E - Format of Control Field 2
55
F - Recommendations for transportation
56
G - Inhibitor tape
57
H - Recommendations on tape durability
57
J - Handling guidelines
58
vii
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ISOIIEC 13421: 1993 (E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the
specialized System for worldwide standardization. National bodies that are members of ISO or IEC participate in the
development of International Standards through technical committees established by the respective organization to deal with
particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, govemmental and non-govemmental, in liaison with ISO and IEC, also take gart in the work.
In the field of information technology, ISO and IEC have established a joint technical committee ISO/IEC JTC 1. Draft
International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75% of the national bodies casting a vote.
International Standard ISO/IEC 13421 was prepared by the European Computer Manufacturers Association (ECMA)
(as Standard ECMA- 182) and was adopted, under a special “fast-track procedure”, by Joint Technical Committee ISO/IEC
JTC 1, Information technology, in parallel with its approval by national bodies of ISO and IEC.
Annexes A to E form an integral part of this International Standard. Annexes F to J are for information only.
Patents
During the preparation of the ECMA Standard, information was gathered on Patents upon which application of the Standard
might depend. Relevant Patents were identified as belonging to Digital Equipment Corporation. I-Iowever, neither ECMA
nor ISO/IEC tan give authoritative or comprehensive information about evidente, validity or scope of patent and like rights.
The patent holders have stated that licences will be granted under reasonable and non-discriminatory terms.
Communications on this subject should be addressed to
Digital Equipment Corporation
334 South Street
Shrewsbury
Massachusetts 015454112
USA
. . .
Vlll
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ISO/IEC 13421:1993 (E)
Introduction
International Standards ISO 9661 and ISOLIEC 11559 specify data interchange on 12,7 mm, 1%track magnetic tape
cartridges.
International Standard 13421 concerns a cartridge of a type different from that of those International Standards. Whilst the
magnetic tape is also 12,7 mm wide, it is recorded on 48 physical tracks. Also the format is different from that of these
previous International Standards. It is characterized by the fact that the physical tracks, recorded and read in pairs, constitute
two groups, the first recorded and read in forward direction, the second in reverse direction.
iX
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ISO/IEC 13421:1993(E)
INTERNATIONAL STANDARD
Information technology - Data interchange on 12,7 mm, 48-track magnetic tape
DLT 1 format
cartridges -
Section 1 - General
1 Scope
This International Standard specifies the physical and magnetic characteristics of a 12,7 mm wide, 48-track magnetic tape
cartridge, to enable interchangeability of such cartridges. It also specifies the quality of the recorded Signals, a format -
called Digital Linear Tape 1 (DLT 1) - and a recording method. Together with a labelling Standard, e.g. ISO 1001, it allows
full data interchange by means of such magnetic tape cartridges.
2 Conformance
2.1 Magnetit tape cartridges
A magnetic tape cartridge shall be in conformance with this International Standard if it satisfies all mandatory requirements
of this International Standard. The tape requirements shall be satisfied throughout the extent of the tape.
2.2 Generating Systems
A System generating a magnetic tape cartridge for interchange shall be entitled to Claim conformance with this International
Standard if all the recordings that it makes on a tape according to 2.1 meet the mandatory requirements of this International
Standard.
23 . Receiving Systems
A System receiving a magnetic tape cartridge for interchange shall be entitled to Claim conformance with this International
Standard if it is able to handle any recording made on a tape according to 2.1.
Normative references
3
The following Standards contain provisions which, through reference in this text, constitute provisions of this International
Standard. At the time of publication, the editions indicated were valid. All Standards are subject to revision, and Parties to
agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent
editions of the Standards listed below. Members of IEC and ISO maintain registers of currently valid international Standards.
ISO 1001: 1986 Information processing - File structure and labelling of magnetic tapes for information interchange.
ISO 1302:1992 Technical drawings - Method of indicating surface texture.
4 Definitions
For the purpose of this International Standard, the following definitions apply.
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ISO/IEC 13421:1993 (E)
41 . Average Signal Amplitude: The average peak-to-peak value of the output Signal from the read head at the
physical recording density of 1 674 ftpmm measured over a minimum length of track of 25,4 mm, exclusive of missing
pulses.
4.2 azimuth: The angular deviation, in minutes of arc, of the mean flux transition line of the recording on a track
from the line normal to the Reference Edge.
4.3 back surface: The surface of the tape opposite the magnetic coating which is used to record data.
4.4 Beginning-Of-Tape marker (BOT): A hole punched on the centreline of the tape towards the end nearest to the
leader.
a unit.
4.5 byte: An ordered set of bits acted upon as
NOTE 1 - In this International Standard, all bytes are 8-bit bytes.
4.6 cartridge: A case containing a Single supply reel of 12,7 mm wide magnetic tape with a leader attached at the
outer end.
47 .
Cyclic Redundancy Check (CRC) Character: A 64-bit Character, generated by a mathematical computation, used
for error detection.
4.8 Early Warning (EW): A Signal generated by the drive indicating the approaching end of the recording area.
4.9 Error-Detecting Code (EDC): A mathematical computation yielding check bytes used for error detection.
4.10 End-Of-Tape marker (EOT): A hole punched on the centreline of the tape towards the end farthest from the
leader.
4.11 Entity: A group of ten Logical Blocks treated as a logical unit and recorded on a logical track.
4.12 Error-Correcting Code (ECC): A mathematical computation yielding check bytes used for the correction of
errors detected by the CRC and the EDC.
normal surface.
4.13 flux transition The Point which exhibits the maximum free-space flux density to the tape
4.14 flux transition spacing: The distance on the magnetic tape between successive flux transitions.
4.15 Logical Block: The two physical blocks simultaneously on, or read from, the two physical tracks ofa
logical track.
4.16 logical track: A pair of physical tracks that are written or read simultaneously.
4.17 magnetic tape: A tape that accepts purposes on
magnetic Signals intended for input, output, and storage
Computers and associated equipment.
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ISO/IEC 13421:1993 (E)
4.18 Master Standard Reference Tape: A tape selected as the Standard for reference field, Signal amplitude,
resolution, peakshift, and overwrite characteristics.
NOTE 2 - The Master Standard Reference Tape has been established by Digital Equipment Corporation.
4.19 Object: A Record or a Tape Mark Block.
4.20 physical block: A set of contiguous bytes recorded on a physical track and considered as a unit.
flux transitions per unit length of track, expressed in flux
4.21 physical recording density: The number of recorded
transitions per millimetre (ftpmm).
4.22 physical track: A longitudinal area on the tape along which a series of magnetic Signals tan be recorded.
4.23 Record: A collection of User Bytes, the number of which is determined by the host.
4.24
Reference Edge: The bottom edge of the tape when viewing the magnetic coating of the tape with the BOT to the
left and the EOT to the right of the observer.
4.25 Reference Field: The Typical Field of the Master Standard Reference Tape.
4.26 Secondary Standard Reference Tape: A tape the characteristics of which are known and stated in relation to
those of the Master Standard Reference Tape.
NOTE 3 - Secondary Standard Reference Tapes tan be ordered under reference SSRT/DLTl until the year 2003 from Digital Equipment Corporation, Tapes
Products Group, 334 South Street, Shrewsbury, Mass. 01545, USA.
It is intended that these be used for calibrating tertiary reference tapes for routine calibration.
4.27 Standard Reference Amplitude (SRA): The Average Signal Amplitude from the Master Standard Reference Tape
when it is recorded with the Test Recording Current at 1 674 ftpmm.
4.28 Standard Reference Current: The current that produces the Reference Field.
4.29
Test Recording Current: The current that is 1,1 times the Standard Reference Current.
4.30
Typical Field: In the plot of the Average Signal Amplitude against the recording field at the physical recording
density of 1674 ftpmm, the minimum field that Causes an Average Signal Amplitude equal to 95 % of the maximum
Average Signal Amplitude.
5 Conventions and notations
51 . Representation of numbers
The following conventions and notations apply in this International Standard, unless otherwise stated.
- In each block and in each field the bytes shall be arranged with Byte 1, the least significant, first. Within each byte the
bits shall be arranged with Bit 1, the least significant, first and Bit 8, the most significant bit, last. This Order applies to
the data, and to the input and output of the error-detecting and error-correcting Codes, and to the cyclic redundancy
characters.
3
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ISO/IEC 13421:1993 (E)
Letters and digits in parentheses represent numbers in hexadecimal notation.
-
The setting of bits is denoted by ZERO or ONE.
- Numbers in binary notation and bit Patterns are represented by strings of ZEROS and ONEs shown with the most
significant bit to the left.
52 .
Names
The names of basic elements, e.g. specific fields, are written with a capital initial letter.
53 . Acronyms
BOT Beginning of Tape
CF1 Control Field 1
CF2 Control Field 2
CRC Cyclic Redundancy Check (Character)
ECC Error-Correcting Code
EDC Error-Detecting Code
EOD End of Data
End of Tape
EOT
End of Track
EOTR
EW Early Warning
FCTl Forward Calibration Track 1
FCT2 Forward Calibration Track 2
Logical End of Tape
LEOT
Modified Frequency Modulation
MFM
RCTI Reverse Calibration Track 1
RCT2 Reverse Calibration Track 2
Standard Reference Amplitude
SRA
6 Environment and safety
Unless otherwise stated, the conditions specified below refer to the ambient conditions in the test or Computer room and not
to those within the tape drive.
61 . Cartridge and tape testing environment
Unless otherwise stated, tests and measurements made on the cartridge and tape to check the requirements of this
International Standard shall be carried out under the following conditions:
-
temperature: 23 OC f 2 OC
-
relative humidity: 40 % to 60 %
-
conditioning before testing: 24 h
62 . Cartridge operating environment
Cartridges used for data interchange shall be capable of operating under the following conditions:
-
temperature: 10 OC to 40 OC
-
relative humidity: 20 % to 80 %
-
wet bulb temperature:
25 OC max.
NOTE 4 - Localized tape temperatures in excess of 49 “C may Cause tape darnage.
4
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ISO/IEC 13421:1993 (E)
If during storage and/or transportation a cartridge has been exposed to conditions outside the above values, it shall be
conditioned before use by exposure to the operating environment for a time equal to, or greater than, the time away from the
operating environment up to a maximum of 2 h. There shall be no deposit of moisture on or in the cartridge.
63 . Cartridge storage environment
,ing conditions:
Cartri dges shall be stored under the follow
-
temperature: 16 OC to 32 OC
-
relative humidity: 20 % to 80 %
-
26 OC max.
wet bulb temperature:
Tapes intended for archiving data for one year or more shall be stored under the following conditions:
-
temperature: 18”Cto26”C
-
relative humidity: 20 % to 60 %
The stray magnetic field at any Point on the tape shall not exceed 4 000 A/m. There shall be no deposit of moisture on or in
the cartridge.
64 . Safety requirements
6.4.1 Safeness
The cartridge and its components shall not constitute any safety or health hazard when used in the intended manner, or
through any foreseeable misuse in an information processing System.
6.4.2 Flammability
The cartridge and its components shall be made from materials which, if ignited from a match flame, do not continue to
burn in a still carbon dioxide atmosphere.
65 . Transportation
This International Standard does not specify Parameters for the environment in which cartridges should be transported.
Annex F gives some recommendations for transportation.
Section 2 - Requirements for the unrecorded tape
7 Mechanical and electrical requirements
7.1 Material
The tape shall consist of a base material (oriented polyethylene terephthalate film or its equivalent) coated on one surface
with a strong yet flexible layer of ferromagnetic material dispersed in a suitable binder. The other surface of the cartridge
shall be coated with a non-ferromagnetic conductive coating.
7.2 Tape length
The length of the tape shall be 355 m min. and 365 m max.
5
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ISO/IEC 13421:1993 (E)
73 . Width of the tape
The width of the tape shall be 12,649 mm =f: 0,010 mm.
The width shall be measured across the tape from edge to edge when the tape is under a tension of less than 0,28 N.
7.4 Total thickness of the tape
The total thickness of the tape at any Point shall be between 12,0 Pm and 14,0 Pm.
7.5 Thickness of the base material
The thickness of the base material shall be between 9,0 Pm and 11 Pm.
Thickness of the magnetic coating
7.6
The thickness of the magnetic coating shall be between 2,0 Pm and 3,0 Pm.
7.7 Thickness of the back coating
The thickness of the back coating shall be between 0,4 Pm and 0,9 Pm.
7.8 Tape discontinuity
There shall be no discontinuities in the tape between the BOT and EOT such as those produced by tape splicing or
perforations.
7.9 Longitudinal curvature
The longitudinal curvature is measured as the departure of the Reference Edge of the tape from a straight line along the
longitudinal dimension of the tape in the plane of the tape surface.
7.9.1 Requirement
Any deviation of the Reference Edge from a straight line shall be continuous and shall not exceed 0,038 mm within any
229 mm length of tape.
7.9.2 Procedure
Measure at a tension of 1,39 N k 0,28 N in a test fixture equipped with two guides spaced at 229 mm. The two guides shall
be spring-loaded to Position the Reference Edge of the tape against two edge control surfaces. Measure the maximum
deviation of the Reference Edge of the tape from the line drawn between the two control surfaces.
7.10 Out-of-Plane distortions
All visual evidente of out-of-plane distortion shall be removed when the tape is subjected to a uniform tension of 0,6 N.
Out-of-plane distortions are local deformations which Cause portions of the tape to deviate from the plane of the surface of
the tape. Out-of-plane distortions are most readily observed when the tape is lying on a flat surface under no tension.
7.11 Cupping
The departure across the width of the tape from a flat surface shall not exceed 0,76 mm.
Procedure
Cut a 1,0 m 2 0,l m length of tape. Condition it for a minimum of 3 hours in the test environment by hanging it so that both
surfaces are freely exposed to the test environment. From the centre Portion of the conditioned tape tut a test piece of
approximately 25 mm length. Stand the test piece on its end in a cylinder which is at least 25 mm high with an inside
diameter of 13,0 mm * 0,2 mm. With the cylinder standing on an Optical comparator measure the cupping by aligning the
edges of the test piece to the reticle and determining the distance from the aligned edges to the corresponding surface of the
test piece at its centre.
6
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ISO/IEC 1342lrl993 (E)
7.12 Roughness of the coating surfaces
7.12.1 Roughness of the back coating surface
The back coating surface shall have an arithmetic average roughness Ra between 0,005 Pm and 0,025 p-n (ISO 1302:N 2).
This measurement shall be made using a contacting stylus of radius 12,5 Fm with a 20 mg load, and a 254 pm cutoff range.
7.12.2 Roughness of the magnetic coating surface
The magnetic coating surface shall have an arithmetic average roughness Ra between 0,005 0 Pm and 0,012 5 Pm (ISO
1302: N 3). For this measurement, the contacting stylus radius shall be 12,5 Pm with a 20 mg load, and a 254 Pm cutoff
range.
7.13 Coating adhesion
The forte required to peel any part of the coating from the tape base material shall not be less than 0,2 N.
Procedure
a) Take a test piece of the tape approximately 380 mm long and scribe a line through the recording coating across the
width of the tape 125 mm from one end.
b) Using a double-sided pressure sensitive tape, attach the full width of the test piece to a smooth metal plate, with the
magnetic coating (recording surface) facing the plate, as shown in figure 1.
c) Fold the test piece over 180”, attach the metal plate and the free end of the test piece to the jaws of a universal testing
machine and set the Speed of the jaw Separation to 254 mm per min.
d) Note the forte at which any part of the coating first separates from the base material. If this is less than 0,2 N, the test
has failed. If the test piece peels away from the double-sided pressure sensitive tape before the forte exceeds 0,2 N, an
alternative type of double-sided pressure sensitive tape shall be used.
e) Repeat a) to d) for the back coating.
Recording surface Scribed line
/
/
Pressufe-sensitive
k-425 mmd
tape
Figure 1 - Measurement of the coating adhesion
7
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ISO/IEC 1342lrl993 (E)
7.14 Layer-to-layer adhesion
Layer-to-layer adhesion refers to the tendency of a layer, when held in close proximity to the adjacent layer, to bond itself to
an adjacent layer so that free and smooth Separation of the layers is difficult.
7.14.1 Requirements
There shall be no evidente of delamination or other darnage to the coatings.
7.14.2 Procedure
Fasten one end of a 914 mm length of tape, magnetic coating inwards, to a horizontally mounted stainless steel
a>
cylinder with a low cold-flow adhesive material.
The dimensions (see figure 2) of the cylinder shall be
b)
- diameter: 12,7 n-rm;
- length: 102 mm.
Attach a mass of 1 000 g to the opposite end of the tape.
Attach, 25,4 mm above the mass, a narrow Strip of double-sided adhesive tape to the magnetic coating.
Slowly rotate the cylinder, so that the tape Winds uniformly around it into a compact and even roll. The double-sided
tape secures the end and prevents unwinding when the mass is removed.
The cylinder with the tape shall then be exposed to the temperature and humidity cycle given in table 1.
f)
Table 1 - Temperature and humidity cycle
Time Temperature RH
85 %
16 h to 18 h 54 “C
4h 54 OC 10 % or less
1 hto2h 21 OC 45 %
Open the end of the roll and remove the double-sided adhesive tape.
g>
Release the free end of the tape.
h)
The outer one or two wraps shall spring loose without adhesion.
0
.
Hold the free end of the tape and allow the cylinder to fall, thereby unwinding the tape.
J)
The tape shall show no coating delamination, except for the 51 mm of tape nearest to the cylinder.
kl
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ISO/IEC 13421:1993 (E)
Figure 2 - Measurement of layer-to-layer adhesion
Modulus of elasticity
7.15
The modulus of elasticity (Young’s modulus) is the ratio of stress to strain in the longitudinal direction.
7.15.1 Requirement
The modulus of elasticity shall be between 5 500 N/mm2 and 8 500 N/mm2.
7.152 Procedure
Clamp a test piece of tape at least 178 mm in length with an initial 102 mm Separation between the jaws of a universal
testing machine with a nominal crosshead Speed of 3 mm/min. Calculate the modulus using the chord of the curve between
the forte at 0 % and 1 % elongation.
7.16 Flexural rigidity
Flexural rigidity is the ability of the tape to resist bending in the longitudinal direction.
7.16.1 Requirement
The flexural rigidity of the tape in the longitudinal direction shall be between 05 x los3 N . mm and 2,9 x 10B3 N . rm-n.
7.16.2 Procedure
Calculate the flexural rigidity D from the following equation:
9
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ISO/IEC 13421:1993 (E)
E x t”
-
-
D
12
where
E = modulus of elasticity obtained from 7.14;
t = measured thickness of the tape in millimetres;
V = Poisson’s ratio, set to 0,33.
7.17 Tensile yield forte
The tensile yield forte required to elongate the test piece by 3 % shall not be less than 14,7 N.
7.17.1 Procedure
Use a static-weighing-constant-rate-of-grip Separation tester capable of indicating the load with an accuracy of * 2 %.
Clamp a test piece of tape at least 178 mm long with an initial 102 mm Separation between the jaws. Elongate the test piece
at a rate of 51 mm/min. until a minimum elongation of 10 % is reached. The forte required to produce an elongation of 3 %
is the tensile yield forte.
7.18 Electrical resistance
7.18.1 Requirement
The electrical resistance of any Square area of the magnetic coating shall
-
be greater than 50 x 106 Q;
-
not exceed 50 x 1012 SZ .
The electrical resistance of any Square area of the back coating shall
- not exceed 100 x 106 Q.
7.18.2 Procedure
Condition a test piece of tape in the test environment for 24 h. Position the test piece over two 24-carat gold-plated (see
figure 3), semi-circular electrodes having a radius r = 25,4 mm and a finish of at least N4, so that the recording surface is in
contact with each electrode. These electrodes shall be placed parallel to the ground and parallel to each other at a distance
d = 12,7 mm between their centres. Apply a forte F of 1,62 N to each end of the test piece. Apply a d.c. voltage of
100 V * 10 V across the electrodes and measure the resulting current flow. From this value, determine the electrical
resistance.
Repeat for a total of five positions along the test piece and average the five resistance readings. For the back coating repeat
the procedure with the back surface in contact with the electrodes.
10
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ISO/IEC 13421:1993 (E)
F
F
Figure 3 - Measurement of electrical resistance
When mounting the test piece, make sure that no conducting paths exist between the electrodes except that through the
coating under test.
NOTE 5 - Particular attention should be given to keeping the surfaces clean.
Inhibitor tape
7.19
This International Standard does not specify Parameters for assessing whether or not a tape is an inhibit
...
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