ISO/IEC 14833:1996
(Main)Information technology — Data interchange on 12,7 mm 128-Track magnetic tape cartridges — DLT 3 format
Information technology — Data interchange on 12,7 mm 128-Track magnetic tape cartridges — DLT 3 format
Specifies the physical and magnetic characteristics of a 12,7 mm wide, 128-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 3 (DLT 3), and a recording method.
Technologies de l'information — Échange de données sur cartouches de bande magnétique de 12,7 mm, 128 pistes — Format DLT 3
General Information
Standards Content (Sample)
INTERNATIONAL
ISO/IEC
STANDARD
First edition
1996-03-I 5
Information technology - Data
interchange on 12,7 mm 128-track
magnetic tape cartridges - DLT 3 format
Technologies de I ‘information
- khange de don&es SW cartouches de
bande magn&ique de 12,7 mm, 728 pistes - Format DLT 3
Reference number
lSO/IEC 14833:1996(E)
---------------------- Page: 1 ----------------------
ISO/IEC 14833:1996 (E)
Page
Contents
1
Section 1: General
1
1 Scope
1
2 Conformance
1
2.1 Magnetic tape cartridges
1
2.2 Generating systems
1
2.3 Receiving systems
1
3 References
1
4 Definitions
1
4.1 Average Signal Amplitude
1
4.2 azimuth
1
4.3 back surface
1
4.4 Beginning-Of-Tape marker (BOT)
2
4.5 byte
2
4.6 cartridge
2
4.7 Cyclic Redundancy Check (CRC) character
2
4.8 Early Warning (EW)
2
4.9 Error-Detecting Code (EDC)
2
4.10 End-Of-Tape marker (EOT)
2
4.11 Entity
2
4.12 Error-Correcting Code (ECC)
2
4.13 flux transition position
2
4.14 flux transition spacing
2
4.15 Logical Block
2
4.16 logical track
2
4.17 magnetic tape
2
4.18 Master Standard Reference Tape
2
4.19 object
2
4.20 page
2
4.21 physical block
2
4.22 physical recording density
0 ISO/IEC 1996
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized
in any form or by any means, electronic or mechanical, including photocopying and microfilm,
without permission in writing from the publisher.
ISO/IEC Copyright Office * Case Postale 56 * CH-1211 Geneve 20 * Switzerland
Printed in Switzerland
ii
---------------------- Page: 2 ----------------------
ISO/IEC 14833:1996 (E)
OISO/IEC
4.23 physical track
4.24 Record
4.25 Reference Edge
Reference Field
4.26
4.27 Secondary Standard Reference Tape
4.28 Standard Reference Amplitu
4.29 Standard Reference Current
4.30 Test Recording Current
4.31 Typical Field
5 Conventions and notations
5.8 Representation of numbers
5.2 Dimensions
5.3 Names
5.4 Acronyms
6 Environment and safety
6.1 Cartridge and tape testing environment
6.2 Cartridge operating environment
6.3 Cartridge storage environment
6.4 Safety
6.4* 1 Safeness
6.4.2 Flammability
4
6.5 Transportation
4
Section 2: Requirements for the unrecorded tape
4
7 Mechanical and electrical requirements
7.1 Material
7.2 Tape length
7.3 Width
7.4 Total thickness
7.5 Thickness of the base material
7.6 Thickness of the magnetic coating
7.7 Thickness of the back coating
7.8 Discontinuity
7.9 Longitudinal curvature
5
7.9.1 Requirement
5
7.9.2 Procedure
5
7.10 Out-of-Plane distortions
5
7.11 Cupping
5
7.12 Roughness of the coating surfaces
5
7.12.1 Roughness of the back coating surface
5
7.12.2 Roughness of the magnetic coating surface
5
7.13 Coating adhesion
6
7.14 Layer-to-layer adhesion
. . .
III
---------------------- Page: 3 ----------------------
OISOHEC
ISO/IEC 14833:1996 (E)
6
7.14.1 Requirements
6
7.14.2 Procedure
7
7.15 Modulus of elasticity
7
7.151 Requirement
7
7.15.2 Procedure
7
7.16 Flexural rigidity
7
7.16.1 Requirement
7
7.16.2 Procedure
8
7.17 Tensile yield force
8
7.17.1 Procedure
8
7.18 Electrical resistance
7.18.1 Requirement
7.18.2 Procedure
7.19 Inhibitor tape
7.20 Abrasivity
7.20.1 Requirement
7.20.2 Procedure
7.21 Light transmittance of the tape and the leader
7.22 Coefficient of dynamic friction
7.22.1 Requirements
8 Magnetic recording characteristics
11
8.1 Typical Field
11
8.2 Signal amplitude
11
8.3 Resolution
11
8.4 Overwrite
11
8.4.1 Requirement
11
8.5 Peak shift
11
8.5.1 Requirement
11
8.52 Procedure
12
9 Tape quality
12
9.1 Missing pulses
12
9.1.1 Requirement
12
9.2 Missing pulse zone
12
9.2.1 Requirement
12
9.3 Tape durability
12
Section 3: Mechanical specifications of the tape cartridge
12
10 General
iv
---------------------- Page: 4 ----------------------
ISO/IEC 14833:1996 (E)
OISO/IEC
13
ottom side and right side
14
ack side and left side
14
15
10.4 Tape leader
16
16
17
10.7 Tape winding
17
&Aoment of inertia
18
10.9 Material
26
equirements for an interchanged tape
Section 4:
26
11 Method of recording
26
11.1 Physical recording density
26
11.2 Channel bit cell length
26
11.2.1 Average Channel bit cell length
26
11.2.2 Long-term average Channel bit cell length
26
11.2.3 Short-term average Channel bit cell length
26
11.3 Flux transition spacing
26
11.4 Read signal amplitude
27
11.5 Azimuth
27
11.6 Channel skew
27
12 Tape format
27
12.1 Reference Edge
27
12.2 Direction of recording
27
12.3 Tape layout
27
12.4 Calibration and Directory Area
28
12.4.1 Scratch Area
28
12.4.2 Guard Area Gl
28
12.4.3 Calibration Tracks Area
29
12.4.4 Guard Area G2
29
Directory Area
12.4.5
29
12.4.6 Guard Area G3
29
12.5 Data Area
30
12.5.1 Physical tracks
30
12.5.2 Width of the physical tracks
30
12.5.3 Logical tracks
30
12.5.4 Locations of the physical tracks
31
12.5.5 Layout of tracks in the Data Area
32
13 Data format
32
13.1 Data Bytes
32
13.2 Logical Blocks
32
13.3 Data Blocks
33
13.4 Types of Logical Blocks
33
13.5 Entities
---------------------- Page: 5 ----------------------
OISO/IEC
ISO/IEC 14833:1996 (E)
33
13.6 Logical Block format
34
13.6.1 Preamble
34
13.6.2 Sync
34
13.6.3 Data Field
36
13.6.4 EDC
36
13.6.5
Control Field 1 (CFl)
37
13.6.6 Control Field 2 (CF2)
38
13.6.7 CRC
38
13.6.8
Postamble
38
14 Use of Logical Blocks
38
14.1 Data Blocks
39
14.2 Filler Blocks
39
14.3 End of Track Blocks (EOTR)
39
14.4 End of Data Blocks (EOD)
39
14.5 ECC Blocks
39
15 Format of Entities
39
16 Error handling
Annexes
40
A - Measurement of light transmittance
43
B - Generation of the Data Blocks CRCs
44
C - ECC generation
47
D - Generation of page CRCs
48
E - Format of MAP entries
49
F - Format of Control Field 1
50
G - Format of Control Field 2
51
H - Recommendations for transportation
52
J - Inhibitor tape
53
K - Recommendations on tape durability
54
L - Handling guidelines
---------------------- Page: 6 ----------------------
OISO/IEC
ISO/IEC 14833:1996 (E)
Foreword
IS0 (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the
specialized system for worldwide standardization. National bodies that are members of IS0 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. IS0 and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non-governmental, in liaison with IS0 and IEC, also take part in the work.
In the field of information technology, IS0 and IEC have established a joint technical committee, ISO/IEC JTCl, 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 10090 was prepared by the European Computer Manufacturers Association (as Standard
ECMA-209) and was adopted under a special “fast-track procedure”,
by Joint Technical Committee ISO/IEC JTCl,
Information technology, in parallel with its approval by national bodies of IS0 and IEC.
Annexes A to G form an integral part of this International Standard. Annexes H to L are for information only.
---------------------- Page: 7 ----------------------
ISO/IEC 14833:1996 (E) OISOHEC
Introduction
International Standard ISO/IEC 13421 concerns a magnetic tape cartridge of a type different from that of International
Standards IS0 9661 and ISO/IEC 11559. Whilst the magnetic tape is also 12,7 mm wide, 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. International Standard ISO/IEC 13962 constitutes a development of the cartridge specified in
International Standard ISO/IEC 13421 in that the number of tracks has been raised from 48 to 112, thus raising the total
capacity of the cartridge accordingly.
This International Standard specifies a further development of the DLT-formatted cartridges. By raising the number of tracks
to 128 and adopting an enhanced format, a further capacity increase is achieved.
---------------------- Page: 8 ----------------------
INTERNATIONAL STANDARD OISO/IEC ISO/IEC 14833:1996 (E)
Information technology - Data interchange on 12,7 mm 1284rack magnetic tape
cartridges - DLT 3 format
Section 1: General
1
Scope
This International Standard specifies the physical and magnetic characteristics of a 12,7 mm wide, 128-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 3 (DLT 3) - and a recording method. Together with a labelling standard, for instance International
- File structure and labelling of magnetic tapes for information
Standard IS0 1001: 1986, Information processing
interchange, it allows full data interchange by means of such magnetic tape cartridges.
2 Conformance
21 . Magnetic 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.
22 . 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.
. Receiving systems
23
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.
3 Normative reference
The following standard contains provisions which, through reference in this text, constitute provisions of this International
Standard. At the time of publication, the edition indicated was 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
edition of the standard indicated below. Members of IEC and IS0 maintain registers of currently valid International
Standards.
IS0 1302: 1992, Technical drawings - Method of indicating su$ace texture.
4 Definitions
For the purposes of this International Standard, the following definitions apply.
41
Average Signal Amplitude : The average peak-to-peak value of the output signal from the read head at the
physical recording density of 1 640 ftpmm measured over a minimum length of track of 25,4 mm, exclusive of missing
pulses.
42 . azimuth : The angular deviation, in minutes of arc, of the mean flux transition line of the recording made on a
track from the line normal to the Reference Edge.
43 . back surface : The surface of the tape opposite the magnetic coating which is used to record data.
44 0 Beginning-Of-Tape marker (BOT) : A hole punched on the centreline of the tape towards the end nearest to
the leader.
---------------------- Page: 9 ----------------------
ISO/IEC 14833tl996 (E) OISO/IEC
45 a byte : An ordered set of bits acted upon as a unit.
NOTE - In this International Standard, all bytes are &bit bytes.
46 0 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.
48 . Early Warning (EW) : A signal generated by the drive indicating the approaching end of the recording area.
49 a Error-Detecting Code (EDC) t 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.
flux transition position : The point which exhibits the maximum free-space flux density normal to the tape
4.13
surface.
4.14 flux transition spacing : The distance on the magnetic tape between successive flux transitions.
4.15 Logical Block : The two physical blocks simultaneously written on, or read from, the two physical tracks of a
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 and retains magnetic signals intended for input, output, and storage
purposes on computers and associated equipment.
Master Standard Reference Tape : A tape selected as the standard for reference field, signal amplitude,
4.18
resolution, peakshift, and overwrite characteristics.
NOTE - The Master Standard Reference Tape is maintained by the Quantum Corporation.
object : A Record or a Tape Mark Block.
4.19
4.20 page : A logical division of a physical block.
4.21 physical block : A set of contiguous bytes recorded on a physical track and considered as a unit.
number of recorded flux transitions per unit length of track, expressed
4.22 physical recording density : The
flux transitions per millimetre (ftpmm).
4.23 physical track : A longitudinal area on the tape along which a series of magnetic signals can be recorded.
Record : A collection of User Bytes, the number of which is determined by the host.
4.24
4.25 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.
4.26 Reference Field : The Typical Field of the Master Standard Reference Tape.
4.27 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 - Secondary Standard Reference Tapes can be ordered under Reference “SSRT/DLTl” until the year 2003 from Quantum Corporation, 333 South
Street, Shrewsbury, Mass. 015454195, USA.
It is intended that these be used for calibrating tertiary reference tapes for routine calibration.
4.28 Standard Reference Amplitude (SRA) : The Average Signal Amplitude from the Master Standard
Reference Tape when it is recorded with the Test Recording Current at 1 640 ftpmm.
4.29 Standard Reference Current : The current that produces the Reference Field.
4.30
Test Recording Current : The current that is 1,l times the Standard Reference Current.
---------------------- Page: 10 ----------------------
OISO/IEC ISO/IEC 14833: 1996 (E)
4.31 Typical Field t In the plot of the Average Signal Amplitude against the recording field at the physical recording
density of 1 640 ftpmm, the minimum field that causes an Average Signal Amplitude equal to 95 % of the maximum
Average Signal Amplitude.
5 Conventions and notations
Representation of numbers
51 l
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.
- Letters and digits in parentheses represent numbers in hexadecimal notation.
- The setting of bits is denoted by ZERO or ONE.
are by strings of
- Numbers in binary notation and bit patterns represented ZEROS and ONES shown with the most
significant bit to the left.
52 . Dimensions
Unless otherwise stated, all dimensions in the format figures are in millimetres with a tolerance of k 50 mm.
53 . Names
The names of basic elements, e.g. specific fields, are written with a capital initial letter.
Acronyms
54 .
BOT Beginning of Tape.
cm Control Field 1
CF2 Control Field 2
CRC Cyclic Redundancy Check (character)
ECC Error-Correcting Code
EDC Error-Detecting Code
End of Data
EOD
End of Tape
EOT
End of Track
EOTR
Early Warning
EW
FCTI Forward Calibration Track 1
FCT2 Forward Calibration Track 2
RCTI Reverse Calibration Track 1
RCT2 Reverse Calibration Track 2
2.7 RLL Run Length Limited (method)
SRA Standard Reference Amplitude
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.
Cartridge and tape testing environment
61 .
of this
Unless otherwise stated, tests and measurements made on the cartridge and tape to check the requirements
International Standard shall be carried out under the following conditions:
23 OC I& 2 OC
- temperature:
40 % to 60 %
- relative humidity:
-
24 h
conditioning before testing:
3
---------------------- Page: 11 ----------------------
OISO/IEC
ISO/IEC 14833:1996 (E)
62 0 Cartridge operating environment
Cartridges used for data interchange shall be capable of operating under the following conditions:
10 “C to 40 “C
- temperature:
-
20 % to 80 %
relative humidity:
-
wet bulb temperature: 25 OC max.
NOTE - Localized tape temperatures in excess of 49 “C may cause tape damage.
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.
Cartridge storage environment
63 l
Cartridges shall be stored under the following conditions:
- temperature: 16 OC to 32 “C
-
20 % to 80 %
relative humidity:
-
wet bulb temperature: 26 OC max.
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 4000 A/m. There shall be no deposit of moisture on or in
the cartridge.
64 a Safety
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, and when so ignited do
not continue to burn in a still carbon dioxide atmosphere.
65 l 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
71 . 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.
72 l Tape length
The length of the tape, measured from BOT to EOT, shall be 355 m minimum and 365 m maximum.
73 0 Width
The width of the tape shall be 12,649 mm * 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.
---------------------- Page: 12 ----------------------
OISO/IEC ISO/IEC 14833:1996 (E)
74 . Total thickness
The total thickness of the tape at any point shall be between 12,0 pm and 14,0 pm.
75 . Thickness of the base material
The thickness of the base material shall be between 9,0 pm and 11,O pm.
76 . Thickness of the magnetic coating
The thickness of the magnetic coating shall be between 2,0 pm and 3,0 pm.
77 Thickness of the back coating
l
The thickness of the back coating shall be between 0,4 pm and 0,9 pm.
78 . Discontinuity
There shall be no discontinuities in the tape between the BOT and EOT such as those produced by tape splicing or
perforations.
79 0 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 * 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 But-of-Plane distortions
All visual evidence 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.
Cut a 1,O m t, 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 cut 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 k 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.
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 pm (IS0 1302:N 2).
This measurement shall be made using a contacting stylus of radius 12,5 pm with a 20 mg load, and a 254 p cut-off 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 (IS0
1302: N 3). For this measurement, the contacting stylus radius shall be 12,5 pm with a 20 mg load, and a 254 pm cut-off
range.
7.13 Coating adhesion
The force required to peel any part of the coating from the tape base material shall not be less than 0,2 N.
---------------------- Page: 13 ----------------------
ISO/IEC 14833:1996 (E) OISO/IEC
Procedure
i. 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.
ii. 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.
iii. 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.
iv. Note the force 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 force exceeds 0,2 N, an
alternative type of double-sided pressure sensitive tape shall be used.
v. Repeat i) to iv) for the back coating.
93-0120-A
Figure 1 - Measurement of the coating adhesion
Layer-to-layer adhesion
7.14
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 evidence of delamination or other damage to the coatings.
Procedure
7.14.2
i. Fasten one end of a 914 mm length of tape, magnetic coating inwards, to a horizontally mounted stainless steel cylinder
with a low cold-flow adhesive material.
ii. The dimensions of the cylinder shall be:
- diameter: 12,7 mm
- length: 102 mm
iii. Attach a mass of 1 000 g to the opposite end of the tape.
iv. Attach, 25,4 mm above the mass, a narrow strip of double-sided adhesive tape to the magnetic coating.
v. 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.
vi. The cylinder with the tape shall then be exposed to the following temperature and humidity cycle:
---------------------- Page: 14 ----------------------
OISO/IEC
ISO/IEC 14833:1996 (E)
Time Temperature
16 h to 18 h
54°C 85 %
4h
54°C 10 % or less
1 hto2h 21 OC 45 %
vii.Open the end of the roll and remove the double-sided adhesive tape.
viii.Release the free end of the tape.
ix. The outer one or two wraps shall spring loose without adhesion.
x. Hold the free end of the tape and allow the cylinder to fall, thereby unwinding the tape.
xi. The tape shall show no coating delamination, except for the 51 mm of tape nearest to the cylinder.
94-0005-A
1ooog
Figure 2 - Measurement of layer-to-layer adhesion
7.15 Modulus of elasticity
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.
7.15.2 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 per minute. Calculate the modulus using the chord of the curve
between the force at 0 % and 1 % elongation.
Flexural rigidity
7.16
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 0,5 x 10m3 N l mm and 2,9 x 10e3 N . mm.
7.16.2 Procedure
Calculate the flexural rigidity D from the following equation:
---------------------- Page: 15 ----------------------
ISO/IEC 14833:1996 (E)
OISO/IEC
D Ext3
2
-
-
-
X
(1 v )
12
E = modulus of elasticity obtained from 7.15
t = measured thickness of the tape in mm
V = Poisson’s ratio, set to 0,33
7.17 Tensile yield force
The tensile yield force required to elongate the test piece by 3 % shall not be less than 14,7 N.
Procedure
7.17.1
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 per minute until a minimum elongation of 10 % is reached. The force required to produce an elongation of 3 % is
the tensile yield force.
Electrical resistance
7.18
7.18.1 Requirement
The electrical resistance of any square area of the magnetic coating shall
- be greater than 50 x lo6 Sz
-
not exceed 50 x 1012 Q
The electrical resistance of any square area of the back coating shall
-
not exceed 100 x 1 O6 a
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, semi-
circular electrodes having a radius r - - 254 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 force F of 1,62 N to each end of the test piece. Apply a d.c. voltage of 100 V t 10 V across
the electrodes and measure the resulting current flow. From this value, determine the electrical resistance.
piece and average the 5 resistance
Repeat for a to tal of 5 positions al ong the test readings. For the back coating repeat the
procedure wi th the bat k surface i .n contact with the electrodes.
93-0122-A
Figure 3 - Measurement of electrical resistance
---------------------- Page: 16 ----------------------
ISO/IEC 14833tl996 (E)
OISO/IEC
When mounting the test piece, make sure that no conducting paths exist between the electrodes except that through the
coating under test.
NOTE - 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 inhibitor tape. However,
annex J gives further information on inhibitor tapes.
7.20 Abrasivity
Tape abrasivity is the tendency of the magnetic coating to wear the magnetic heads.
7.20.1 Requirement
The depth of the wear pattern in a ferrite wear bar shall be less than 1,27 pm.
7.20.2 Procedure
A test piece 61 m in length shall be passed for 100 passes (50 cycles) over a rectangular bar of manganese zinc ferrite. The
bar shall be 0,3 mm wide and its top surface shall be rounded off with a radius r, = 5
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.