ISO 18933:2006

Imaging materials - Magnetic tape - Care and handling practices for extended usage

ISO 18933:2006 concerns the care and handling of magnetic recording tape during use. It addresses the issues of physical integrity of the medium necessary to preserve access to the data (information) recorded on the tape. ISO 18933:2006 recommends handling procedures to maximize the effective life of magnetic tape. While some of the recommendations in ISO 18933:2006, such as staff training, apply specifically to large-scale or archival usage, the basics of all recommendations in this International Standard can and should be applied in all circumstances where the desired result is long-term usage of the medium whether archival, commercial or personal. ISO 18933:2006 addresses the following subjects: handling techniques, including common hazards and methods to mitigate those hazards; handling environments, including pollutants, temperature and humidity, lighting, magnetic fields and robotics; use of tape, including inspection, playback, mounting/loading and removing, winding speed, tension and robotic systems; cleaning and maintenance techniques, including contaminants, cleaning methods and frequency; transportation, both in-house and shipping outside the storage facility; disasters, including water, fire, construction and post-disaster procedures; staff training, including schedule for training and contents of the training programme; archival issues.

Matériaux pour l'image — Bande magnétique — Précautions et pratiques de manutention pour usage prolongé

General Information

• Status: Withdrawn
• Publication Date: 12-Jul-2006
• Withdrawal Date: 12-Jul-2006
• ICS: 35.220.22 - Magnetic tapes
• ICS: 37.040.99 - Other standards related to photography
• Technical Committee: ISO/TC 42 - Photography
• Drafting Committee: ISO/TC 42/WG 5 - Physical properties and image permanence of photographic materials
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 11-May-2012
• Completion Date: 13-Dec-2025

Relations

• Revised: ISO 18933:2012 - Imaging materials - Magnetic tape - Care and handling practices for extended usage
• Effective Date: 19-Nov-2011

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 18933
First edition
2006-07-15
Imaging materials — Magnetic tape —
Care and handling practices for extended
usage
Matériaux pour l'image — Bande magnétique — Précautions et
pratiques de manutention pour usage prolongé

Reference number
©
ISO 2006
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©  ISO 2006
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ii © ISO 2006 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Tape pack integrity . 6
5 Contamination. 9
6 Handling techniques. 11
7 Environment . 14
8 Inspection . 17
9 Cleaning and maintenance . 18
10 Transportation. 20
11 Disasters. 22
12 Staff training. 24
13 Minimum handling requirements checklist. 25
Annex A (informative) Numbering system for related International Standards. 27
Bibliography . 29

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 18933 was prepared by Technical Committee ISO/TC 42, Photography.
iv © ISO 2006 – All rights reserved

Introduction
This International Standard is one of a series of International Standards dealing with the physical properties
and stability of imaging materials. To facilitate identification of these International Standards, they are
assigned a number within the block from 18900 to 18999 (see Annex A).
Magnetic recording tape has served as a major means of processing, distributing and preserving information,
including video, audio, computer and other data since the 1930s. Unlike earlier data-recording media such as
paper and photographic material, the information recorded on magnetic tape is not directly human-readable
and requires a machine interface and interpretation. In addition, the machine/medium interface must occur
within precise conditions in order for the machine interpretation to be accurate. Therefore, the physical
integrity of magnetic tape necessary to provide a proper interface with the interpreting machinery is critical.
Correct care and handling is essential to preserve the needed physical integrity of magnetic tape both for
short-term usage and long-term archiving.
Magnetic tape has proven itself an easy-to-use and versatile medium. Yet despite the substantial resources
put into creating recordings and the historical, intellectual and financial assets they represent, tapes often are
not treated as valuable objects. Many important and unique recordings are lost due to inadequate care and
handling of the tape. This poses problems for users who wish to preserve the content. Among these problems
are the following.
a) Improper handling can damage magnetic tapes and compromise the future ability to retrieve content.
b) Due to the enormous volume of existing tapes, the impracticality and cost of making copies of each and
every one frequently results in large numbers of unique records being subjected to excessive use and
wear without any back-up or protection. Repeated use of magnetic tape can cause wear or physical
damage that shortens its effective life.
c) Some magnetic tapes are known to have a finite shelf life and will eventually decay. Recorded documents
on these tapes must be copied to new media before decay precludes access.
d) The ability to play back a tape in the future depends on the existence of functional playback equipment.
As new tape formats become popular, equipment manufacturers discontinue the production and support
of older, superseded equipment. Eventually, usable equipment to play older, obsolete magnetic tape
formats becomes impossible to find. Before this occurs, a migration plan should be in place.
Like all media, magnetic tape is subject to both damage and decay. Consequently, its effective life can
increase or decrease significantly depending on the conditions under which it is stored and handled. This
International Standard contains recommendations for the care and handling of magnetic tape.
Recommendations for the preservation and storage of polyester-base magnetic tape appear in ISO 18923.
Following these recommendations promotes the physical integrity of the media and increases the effective life
of magnetic tape.
INTERNATIONAL STANDARD ISO 18933:2006(E)

Imaging materials — Magnetic tape — Care and handling
practices for extended usage
1 Scope
This International Standard concerns the care and handling of magnetic recording tape during use. It
addresses the issues of physical integrity of the medium necessary to preserve access to the data
(information) recorded on the tape. This International Standard recommends handling procedures to maximize
the effective life of magnetic tape. Faulty handling, packing and transporting techniques and methods often
cause damage to magnetic tape and the content recorded thereon. Extending the longevity of magnetic tape
requires the identification of appropriate handling methods and well-developed training programmes.
While some of the recommendations in this International Standard, such as staff training, apply specifically to
large-scale or archival usage, the basics of all recommendations in this document can and should be applied
in all circumstances where the desired result is long-term usage of the medium whether archival, commercial
or personal.
This International Standard addresses the following subjects:
⎯ handling techniques, including common hazards and methods to mitigate those hazards;
⎯ handling environments, including pollutants, temperature and humidity, lighting, magnetic fields and
robotics;
⎯ use of tape, including inspection, playback, mounting/loading and removing, winding speed, tension and
robotic systems;
⎯ cleaning and maintenance techniques, including contaminants, cleaning methods and frequency;
⎯ transportation, both in-house and shipping outside the storage facility;
⎯ disasters, including water, fire, construction and post-disaster procedures;
⎯ staff training, including schedule for training and contents of the training programme;
⎯ archival issues.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 14644-1:1999, Cleanrooms and associated controlled environments — Part 1: Classification of air
cleanliness
ISO 14644-2:2000, Cleanrooms and associated controlled environments — Part 2: Specifications for testing
and monitoring to prove continued compliance with ISO 14644-1
ISO 18923:2000, Imaging materials — Polyester-base magnetic tape — Storage practices
AES22:1997, AES recommended practice for audio preservation and restoration — Storage and handling —
Storage of polyester-base magnetic tape
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
acclimatization
process of conditioning material from one set of temperature/moisture conditions to another
NOTE Sometimes called “staging”.
3.2
backcoat
〈magnetic tape〉 rough surface layer added to the back of the basefilm to increase friction and minimize
slippage between tape strands
3.3
basefilm
plastic (polymer) substrate to which the magnetic layers are attached
NOTE Sometimes called “the base”.
3.4
binder
〈magnetic tape〉 plastic (polymer) in which the magnetic particles are bound in order to create the recording
layers of the tape and which binds the recording layers to the basefilm
3.5
carrier
medium upon which the information is recorded
3.6
carton box
outer container that can hold one or more individual units and may be a fabrication of paper, card stock or
plastic
3.7
cartridge
housing for a roll of recording material, such as photographic film or magnetic tape, wound on a single hub or
reel
SEE cassette (3.8)
3.8
cassette
housing for a roll of recording material, such as photographic film or magnetic tape, whose ends are attached
to two hubs or reels
3.9
cinching
tape folding back upon itself within the tape pack
3.10
class 100 000 cleanroom
controlled environment in which the levels of airborne contaminants meets the requirements of ISO 14644-1
NOTE The number of particles larger than one micrometre (one micron) in one cubic foot (0,028 3 cubic meters) of
air shall not exceed 100 000. Class 100 000 is like a dust-free office. Class 10 000 requires cleanroom clothing.)
2 © ISO 2006 – All rights reserved

3.11
conditioning
exposure of a specimen to air at a given relative humidity and temperature until equilibrium is reached
3.12
container
box, can or carton used for storage and shipping of recording materials
NOTE Reels, cassettes, cartridges, or shells are not containers; the box into which a reel, cassette, cartridge or shell
is placed is defined as a container.
3.13
copy
reproduction of the information from a master
3.14
domain
cluster of the embedded magnetic particles which all align in the same north-south direction
NOTE Sometimes referred to as a “magnetic domain”.
3.15
extended-term storage conditions
storage conditions suitable for the preservation of recorded information having permanent value
3.16
flange
fixed or removable circular disc that is connected to the hub to make a reel for the purpose of protecting the
roll of recording materials
SEE reel (3.34)
3.17
flange pack
condition where the whole tape pack rests against one flange
3.18
format
dimensions of the magnetic recording and its assembly as well as the physical and magnetic specifications of
the recording on the tape
3.19
heads out
configuration of magnetic tape stored on its reel or in its cassette such that the tape is positioned to play from
the beginning of the recorded information
3.20
hub
cylindrical object around which the recording material is wound
3.21
hydrolysis
decomposition involving a reaction with water that results in the splitting of chemical bonds
3.22
leader
flexible plastic or paper strip which can be spliced to either end of a roll of recording material
NOTE This practice is not recommended for extended-term storage.
3.23
leafing
multiple popped strands in a magnetic-tape wind
SEE popped strand (3.32) and stepped pack (3.41)
3.24
library wind
low-speed rewind at controlled tension to achieve a smooth tape pack (typically 1 m/s to 3 m/s)
3.25
loose pack
undesirable pack condition in a roll of recording material, such that the outer portion of the roll can be moved
and tightened by pulling on the end
3.26
magnetic field intensity
magnitude of the magnetic field, in amperes per meter, at a point in space
3.27
master
the original or primary recording of the data or any version of the data (e.g. camera master, edited master,
foreign language master)
3.28
medium
media, pl
material on which information is recorded
SEE carrier (3.5)
3.29
medium-term storage conditions
storage conditions suitable for the preservation of recorded information for a minimum of 10 y
3.30
migration
transferring information from one format to another
3.31
oligomer
low molecular-weight polymer which can be produced by degradation of the magnetic tape binder
3.32
popped strand
lateral displacement of a single strand or wrap of magnetic tape extending beyond the plane of the tape pack
SEE leafing (3.23) and stepped pack (3.41)
3.33
print-through
unintentional magnetic transfer of the recording on one layer of magnetic tape to the adjacent layers during
storage on a reel/hub
3.34
reel
metal or plastic hub or core with flanges (protective sides) onto which recording material is wound
4 © ISO 2006 – All rights reserved

3.35
shell
outer housing of a cassette or cartridge
3.36
slot
space or slit in the winding surface of a reel or hub
3.37
splice
union of two pieces of recording or leader material to form a single piece
3.38
splicing tape
paper or plastic strip coated with a thermal or pressure-sensitive adhesive, used in splicing
3.39
spoking
deformations in a roll pack that appear radially outward and disrupt the circular nature of the wind
3.40
staging acclimatization
process of conditioning material from one set of temperature/moisture conditions to another
3.41
stepped pack
multiple adjacent strands of magnetic tape extending beyond the level of a tape pack
SEE leafing (3.23) and popped strand (3.32)
3.42
storage environment
conditions for storing materials, i.e., temperature, relative humidity, cleanliness of facilities and atmospheric
pollutants
3.43
tails out
configuration of magnetic tape stored on its reel, or in its cassette, such that the tape must be fully rewound in
order to correctly play from the beginning of the recorded information
3.44
tape pack
length of magnetic tape wound on a reel or hub
3.45
wind
physical appearance and tension of the magnetic tape pack
or
process of transferring a roll of recording material from one spool or reel to another
3.46
windows
openings in the flanges of a tape reel, sometimes called “windage holes”
or
physical spacings in the tape pack
or
clear viewing port of a cassette
4 Tape pack integrity
4.1 General
The physical integrity of the tape pack shall be maintained to avoid damage to the tape and allow for proper
retrieval of the recorded content. Tape pack integrity is dependent on several variables and loss of pack
integrity can have a variety of negative effects.
4.2 Common pack problems
4.2.1 Pack deformation
Edge damage and tape deformation will alter the quality of the tape pack, resulting in spoking or a
lipped-edged pack (see Figure 1).
4.2.2 Flange pack
If the tape pack is against one flange, then there is a misalignment between the tape reel and the tape edge
guide nearest the tape reel.
4.2.3 Pack slippage
Vibration or impact will often result in slippage of the pack causing edge damage if the winding tension is too
low. The pack is most susceptible to slippage while a tape is held horizontally.
4.2.4 Pack penetration or abrasion
Any portion of the tape pack that is exposed is especially vulnerable to damage. Fingers shall not be inserted
through the window of a flange except in an empty reel when threading an open reel tape.
4.2.5 Edge compression
Mounting and unmounting large reels of tape requires special care. Tape reels shall be handled by the hub
and the flanges shall not be squeezed. Compressing the flanges can crack the magnetic coating on tape
edges and deform the basefilm resulting in poor head-to-tape contact. Tape with laterally misaligned strands
is extremely susceptible to edge compression damage [see popped strand (3.32)].
4.3 Pack tension
4.3.1 General
If a tape is not wound at the proper tension, the tape pack is likely to become distorted during storage. When a
distorted pack is unwound, tape surface deformation will be noticed at spacings equal to the circumference of
the tape pack at that point. Tape surface deformation is likely to cause poor head-to-tape contact.
NOTE Most tape deformation can be returned to normal by a knowledgeable tape restoration professional – except
where a tape layer has been folded.
4.3.2 Tension control
The tape tension is controlled by the design and maintenance of the tape machine. Tape tension can be
measured by a technician with a special tape tension gauge.
6 © ISO 2006 – All rights reserved

4.3.3 Winding tension
Tape shall be wound on a hub, not touching a flange, within a range of tensions that allows the tape to
maintain a uniform pack without imposing unnecessary longitudinal stress.

a)  Good pack b)  Popped strands c)  Slipped pack d)  Flange pack with lipped edge
Key
1 reel flange
2 tape pack
3 hub
Figure 1 — Examples of tape packs
4.4 Tape winding speed
4.4.1 General
The speed of the tape while it is being packed on to the reel can affect the tape pack. When tape is wound at
high speed, air is trapped between the tape strands and can cause pack irregularities. At play or record
speeds, air is not trapped between layers and the tape will develop a smooth-edged pack, unless the tape
edges have been damaged.
4.4.2 Library wind
Library wind mode shall be used, when available, before storage. This mode is a special option on some tape
machines that wind the tape at low speed.
4.4.3 Winding loose packs
If a tape pack is loose, it shall not be run at fast forward or fast rewind speeds. The tape shall be run in play
mode to the end and then rewound. Very loose tape packs shall be hand wound or wound on a machine with
reduced tension to avoid cinching and other damage. For cassette tapes, this may require special handling or
machinery and expert assistance to avoid tape damage.
4.5 Tape, hub and reel design
4.5.1 General
Design elements of the tape, hub and reel can affect the tape pack.
4.5.2 Backcoat surface of the tape
Backcoated tape has a rough surface that increases friction, thus minimizing slippage between tape strands
and loss of tape pack integrity.
4.5.3 Splices
Tapes shall not be spliced except as required for repair prior to playback or when the splice is part of the
manufacturing process (i.e. attaching tape ends to leader). The problems created by splices include
deformation, delamination, adhesive bleed, alignment problems and tape head damage.
4.5.4 Hub diameter
Pack slippage is less likely to occur on reels where the ratio of the outer pack to hub diameter is less than 2,5.
4.5.5 Flangeless hubs
Sometimes magnetic tape is stored on flangeless hubs. When this practice is used, the following
recommendations shall be observed.
a) Only backcoated tape designed for storage on a flangeless hub shall be stored in this manner.
Non-backcoated tape will not wind properly and is at high risk of falling off the tape pack.
b) Tape tension is especially critical; too loose a wind will result in immediate disintegration of the tape pack.
c) The loose end of the tape shall be fixed down with non-residue-producing adhesive tape. Tapes shall be
held only between the hub and the outside wind, without touching the surface of the tape pack.
d) Extreme caution shall be used when handling tapes without flanges. Loose tapes shall be rewound on a
correctly adjusted tape machine.
4.5.6 Reel flanges with openings (windows)
When tape is wound at high speed (fast forward or rewind), air is trapped between the tape strands but can
escape if the flange is designed with openings. This ensures good contact between the surfaces of adjacent
strands.
4.5.7 Cassettes and cartridges
Tape cassettes and cartridges shall be wound entirely to one end at play speed or to a special parking area
designated by the machine manufacturer to avoid deformation of recorded sections of the tape from prolonged
contact with internal guide posts.
8 © ISO 2006 – All rights reserved

5 Contamination
5.1 General
Magnetic tapes are highly susceptible to contamination.
Figure 2 shows the relative size of debris commonly found on magnetic recording tapes and in tape machines,
relative to the head-to-tape spacing. It is clear from this diagram that even the smallest airborne particles can
result in errors if the debris gets between the head and the tape.

Key
1 video head
2 cotton fibre
3 finger print
4 gap
5 dust
6 human hair
7 magnetic tape surface
Figure 2 — Debris on the surface of the tape
Figure 3 is a photograph of a small section of tape that has been covered with very fine iron particles to show
ten recorded video tracks. The “mountain” in the middle of the photograph is a small piece of debris. It is
surrounded by empty space caused when the video head skipped over the debris and did not record part of
two video tracks.
a
One track.
Figure 3 — Loss of data due to a clump of debris on the surface of the tape
5.2 Particulate contaminants
Particulate contaminants will block access to material recorded on a tape and can cause physical damage to
both tape and machinery. Dust, smoke and debris-generating objects or materials (e.g. carpets, draperies,
unsealed insulation, packaging blankets and other padding materials, fibrous wall coverings and furnishings)
shall not be present in any area where extended-life tapes are being handled or used. In areas where sound
levels shall be minimized, special non-debris generating material shall be used.
5.3 Gaseous contaminants
Gaseous pollutants, such as exhaust fumes and fumes from ammonia- and chloride-based cleansers, cause
chemical reactions that are harmful to magnetic recording tapes. Positive air pressure shall be maintained in
tape usage areas to reduce ingress of gaseous contaminants (see 7.3.2). Ammonia- and chloride-based
cleansers shall not be used in tape handling or usage areas.
5.4 Organic contaminants
5.4.1 General
Organic contaminants damage tape in two ways: by directly damaging the tape and by attracting and holding
other contaminants in contact with the tape.
5.4.2 Human-transferred contaminants
Personnel shall wash their hands before handling magnetic tapes or protective cases since human skin is
constantly being shed. Epidermal oils and artificial substances such as lotions are easily transferred to
magnetic recording tape. Such oils can be destructive to the tape and may carry other damaging
10 © ISO 2006 – All rights reserved

contaminants and debris. Consequently, small flakes of skin and oily fingerprints are among the most common
contaminants found on tape.
5.4.3 Consumables
Magnetic tape use and handling areas shall be kept free of food, beverages and smoke. Food and drink pose
a threat to magnetic recording tape both because they contain destructive agents and because they can
attract and hold other pollutants. Many foods, especially those that contain sugars, have adhesive
characteristics that will cause tape to stick to itself and other objects. Decaying food also can result in fungal
growth or the attraction of destructive vermin.
5.4.4 Biological contaminants
The most common biological contaminant of tape is fungus. Fungus shall be considered toxic and treated with
great care. Unprotected personnel shall not handle tapes containing fungus.
5.5 Protective cases
Protective cases shall not be opened, and magnetic recording tapes shall not be removed from their cases, in
environments where a large amount of particulate matter is present or is likely to be generated such as in
shipping rooms or machine shops.
5.6 Field usage
For field applications, tapes shall be transported in their protective cases and left in the recorder only during
use. In the field, tapes and tape cases shall be shielded at all times from exposure to moisture, temperature
extremes, dust and sunlight.
6 Handling techniques
6.1 General
Magnetic tape is easily damaged by improper handling. Proper techniques shall be used when handling
magnetic tapes to avoid damaging the medium in ways that will shorten the usable life of the tape or interfere
with the future ability to retrieve information from the tape.
6.2 Vertical/horizontal tape orientation
6.2.1 Tape position
The position of the tape during handling and the user’s grip will affect the tape’s susceptibility to damage.
6.2.2 Reel-to-reel tapes
Reels of magnetic recording tape shall be held vertically, by the centre hub or supported by the edges of the
flanges, without putting pressure on the flat surfaces of the flanges.
6.2.3 Cassettes and cartridges
Cassettes and cartridges shall be positioned vertically except when it is necessary to change their orientation
in order to insert or remove them from equipment. Cassettes and cartridges shall be held touching only the
rigid outer casing or shell and not the movable lid or the hub.
6.2.4 Transportation
Magnetic tape recordings shall be transported, in-house as well as between facilities, vertically in their
protective cases. Tapes shall be removed from their cases only for inspection or immediate use.
6.2.5 Removal from protective cases
Protective cases shall be placed horizontally on a clean, flat, uncluttered surface when opening the case to
remove the magnetic recording tape. Other than during this operation or when positioning in a machine,
magnetic tapes shall not be left in a horizontal position.
6.3 Handling access
6.3.1 Staff
Only trained staff shall hold and use master magnetic tape recordings.
6.3.2 Physical contact
Magnetic recording tape shall not be touched by fingers except at the beginning and the end of the tape.
When magnetic tape must be touched, hands and fingers shall be washed immediately prior to performing the
work and/or dye-free, lint-free gloves shall be worn.
6.3.3 Frequency of access
Master recordings shall be handled and moved as infrequently as possible. Procedures shall be established to
provide alternate copies of the recordings when frequent usage is required.
6.4 Use of force
6.4.1 General
Magnetic recording tapes shall be held in ways that minimize stress (e.g. pressure or torque) on the tape and
the support structure.
6.4.2 Loading force
Excessive force shall not be used to load a magnetic recording tape into either a container or a machine.
Pressure shall only be exerted in the hub area for tapes on reels.
6.4.3 Releasing force
Releasing or putting magnetic recording tapes on any surface shall be done gently, minimizing vibration and
impact. Tapes and protective cases should never be thrown or dropped.
6.4.4 Flange compression
When the flanges on a reel are forced closer together, serious deformation or crushing damage to the tape
can result. Typical actions that cause flange compression are:
a) picking up or holding a flanged reel from the outer edge with the fingers on one flange and the thumb on
the other flange (unfortunately, this is often seen as the most common and convenient way to hold a reel);
b) stacking tapes or other objects on top of an unprotected reel;
c) sudden impact such as dropping a tape or hitting it against the edge of a table;
d) forced closing of a protective case on a tape when there is other material in the case.
12 © ISO 2006 – All rights reserved

6.5 Tape condition
6.5.1 General
Tapes shall be as secure from damage as possible before handling or transportation.
6.5.2 Open reels
During handling or transport, the outer wrap of tapes on open reels shall be secured by the use of non-
destructive hold-down tape or reel guard bands specifically made for this purpose.
6.5.3 Cassettes and cartridges
Many cassettes and cartridges have internal mechanisms that prevent the hubs from turning. Cassettes and
cartridges that do not have such mechanisms shall be handled and transported with suitable retainers or in
protective cases that are designed to prevent hub movement.
6.5.4 Tape position on hub
Tapes shall be wound to the end before being removed from the machine and before storage. The tape pack
shall be as smooth as possible.
6.5.5 Robotic systems
Some robotic systems are designed to wind the tape to special “parking” zones on the tape for
threading/unthreading of the tape. But, when a tape is removed from the robotic system, it shall be wound to
the end.
6.6 General handling
6.6.1 General
Handling of master tapes shall be done so as not to compromise the ability of future users to gain access to
the recording.
6.6.2 Labelling
All tapes and their containers shall be clearly labelled with all information necessary to identify content for the
life of the recording. Labels shall not interfere with the use of the tape.
6.6.3 Print-through
Print-through can be accelerated by high winding tension, magnetic fields and heat. Analogue audio tapes
shall be stored on the take-up reel (tails out) to minimize the effects of print-through [see print-through (3.33)].
Print-through is reduced by rewinding several times.
6.6.4 Erasure
The record protection feature of all master cassettes shall be activated immediately after they have been
recorded (see also 7.4).
Erasure of tape content is a virtually non-recoverable problem. Erasure requires close proximity of a strong
magnetic field. The strength of field necessary is seldom found in the environment, and erasure of tape data is
almost always the result of human error or intent.
7 Environment
7.1 General
During use and handling, many environmental factors affect the functioning and life expectancy of magnetic
recording tape. Among the most critical factors are temperature, humidity, cleanliness and the presence of
potential contaminants.
Magnetic tape life is affected by chemical deterioration, including binder hydrolysis, loss of lubricant and
binder/base separation. The rate at which these events occur varies depending on the chemical formulation
used by the manufacturer and the environmental conditions to which the tape is exposed. Although there have
been numerous studies about tape longevity and stability that have produced valuable qualitative information,
an accelerated life test that produces meaningful quantitative data does not exist yet. Hence, no method is
known which will indicate the specific life expectancy of various brands and formulations of magnetic tape.
The environmental conditions given in this clause shall be followed for tapes intended for extended life. They
are also recommended for all handling environments in order to prolong the life of all tapes.
7.2 Temperature and humidity
7.2.1 Environmental condition
Magnetic tape life is influenced directly by temperature and humidity. Master tapes shall be handled at stable
temperatures between 18 °C and 25 °C and at stable relative humidities between 15 % and 50 %.
7.2.2 Life expectancy
Life expectancy increases when magnetic tape is stored in a cool, dry environment characterized by stable
temperatures and humidity. Time out of the recommended storage environment shall be minimized, so as to
maximize tape life. For acceptable storage environments, see ISO 18923.
7.2.3 Water avoidance
A major cause of chemical degradation of magnetic recording tape is the interaction with water, called
hydrolysis, either directly or through absorption of moisture from the air. Precautions shall be taken to mitigate
possible incursion of water due to condensation, floods, leaks and sprinklers, and to limit excess humidity.
Walls and enclosures in use- and handling-areas shall be designed to prevent condensation of moisture on
interior surfaces. All use- and handling-areas shall be above basement level where water damage is most
prevalent. Floors shall be provided with drains or other means of water removal. Drains shall have systems to
prevent liquids or sewage from backing-up into the facility. All work and handling surfaces shall be elevated off
the floor.
7.2.4 Fungus
Extended exposure to humidities of approximately 65 % RH will promote fungal growth.
7.3 Air quality
7.3.1 General
Impurities in the air may be harmful to magnetic tape. An expert should be consulted about removal of harmful
particles from the air.
14 © ISO 2006 – All rights reserved

7.3.2 Air flow
Positive air pressure in use- and handling-areas shall be maintained relative to adjacent hallways, rooms and
facility exteriors to minimize contamination from outside sources.
7.3.3 Cleanroom specifications
Record, playback and inspection usage of magnetic recording tape shall be performed in a cleanroom
environment class 100 000 or better [see class 100 000 cleanroom (3.10)].
7.4 Magnetic fields
7.4.1 General
External magnetic fields are observed most frequently near motors and transformers (e.g. elevators and lifts),
but potentially damaging fields can be generated by some headphones, speakers, microphones, magnetic
cabinet latches and magnetized tools. Care shall be taken during handling and transportation to avoid placing
tapes in close proximity to potential sources of magnetic fields.
7.4.2 Levels
Within use- and handling-areas, the peak intensity of external steady state (DC) fields shall not exceed
4 kA/meter (50 Oersteds) and the peak intensity of external varying (AC) fields shall not exceed 800 A/meter
(10 Oersteds).
7.4.3 Separation distance
Most sources of magnetic fields are localized and the field intensity falls off rapidly with separation (a few
centimeters' separation from the source will usually provide adequate protection).
7.4.4 Print-through
Magnetic fields, heat and high winding tension accelerate print-through (see 6.6.3).
7.5 Light exposure
Magnetic recording tapes and their protective cases can be damaged by exposure to ultraviolet (UV) light.
Tapes and protective cases shall not be exposed to direct sunlight. Use-areas should not have outside
windows, skylights or other sources of natural lighting. To minimize UV damage, artificial UV sources such as
fluorescent lighting shall have appropriate UV filters installed in accordance with the manufacturer's guidelines,
and tapes shall be kept in their protective cases except when in active use. To reduce UV damage to
protective cases and labels, lights shall be turned off in use- and handling-areas when the areas are not
occupied.
7.6 Acclimatization
7.6.1 General
Environments may vary slightly from the general guidelines depending on the specific use, the duration of
exposure during specific use, and the practical realities of use in environments where human control of the
environment is severely limited. Cooler and drier environments are better for tape longevity; however, at the
coldest and driest levels acceptable for long-term storage, some tapes cannot be used immediately in
playback mode. Tapes stored in such conditions shall be acclimatized to a different set of environmental
conditions for playback to be both safe and successful. Acclimatization is the process of altering temperature
and moisture content of magnetic tape so that it can be used at a substantially different temperature and/or
humidity level. A compromise between energy input, longevity, comfort of handling, access time and health
requirements of operating staff shall be achieved. In tropical climatic zones, a slightly higher temperature for
the handling environment (25 °C) may be unavoidable, with the clear understanding that storage and handling
environments shall not differ substantially unless acclimatization is properly carried out.
7.6.2 Common problems
Failure to acclimatize tapes can result in pack slippage, creasing during handling, mis-tracking during
playback and moisture condensation. Tapes exposed to temperatures above 25 °C or relative humidities
above 50 % shall be acclimatized before playback.
7.6.3 Dimensional changes
Magnetic recording tape will expand and contract when exposed to different levels of temperature and
humidity. Depending on the format, tapes recorded at one temperature/humidity level may suffer from
mis-tracking if playback is attempted at a substantially different temperature/humidity level. If the differential
between the initial environment and the destination environment is particularly great, it may be necessary to
acclimatize gradually or in steps.
7.6.4 Condensation
The most common reason to acclimatize tape is to avoid moisture condensation. Moisture condensation can
occur when moving tapes to cool conditions from warm, humid environments. This can be avoided by use of a
staging room or an enclosure. The tape shall not be removed from the staging environment until it is above
the dew point of the use environment.
7.7 Marginal environments
7.7.1 General
To mitigate negative environmental factors, magnetic recording tapes shall not be removed from the buffering
effect provided by their protective cases when in packing, shipping or receiving areas. To further buffer tapes
from exterior environmental factors, they shall be packed in additional, non-dusting, insulating material for
shipment.
7.7.2 Shipping and receiving areas
Temporary fluctuations beyond the accepted temperature and humidity ranges are permissible as long as the
environment is returned to recommended levels in less than one hour. Staging or holding areas for shipping
and receiving shall not have direct access to the outdoors. Two sets of doors shall be used to minimize the
impact of external temperatures and contaminants. Packing and unpacking shipments produces unavoidable
debris substantially in excess of recommended levels. Areas where these activities are performed shall be
cleaned on a regular basis to minimize the accumulation of debris.
7.7.3 Field environments
In the field, magnetic recording tapes and protective cases shall be shielded from environmental extremes,
including direct exposure to water, dust and sunlight. Tapes shall be kept in their protective cases unless they
are being used. When possible, tapes not needed for immediate use shall be kept in an air-conditioned space
(e.g. hotel room, office, electronic news gathering (ENG) uplink van). As recording equipment is an integral
part of the field use environment, these precautions shall be applied to the equipment as well as to the tape.
7.7.4 Robotic environments
Robotic recording and playback systems shall be carefully examined to determine that they do not exceed any
of the conditions for heat, relative humidity, excessive vibration and movement, dust or dirt, moisture or
magnetic fields, as set forth in this document. Robotic storage and retrieval systems shall also comply with
ISO 18923.
16 © ISO 2006 – All rights reserved

8 Inspection
8.1 General
A comprehensive plan for the inspection of magnetic tape before use is essential in order to:
a) prevent damage to the tape itself;
b) extend tape life;
c) prevent damage to the machinery on which it is transported or played back.
Periodic inspection during storage is also essential to prevent premature loss of materials. See AES22:1997
and ISO 18923 for information regarding inspection related to storage of magnetic tape. Tape shall be
physically inspected before every major change in status; e.g. before shipment, before playback and before
placement in storage.
8.2 Seven-
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