SIST EN 61965:2004

SLOVENSKI SIST EN 61965:2004
STANDARD
julij 2004
Mechanical safety of cathode ray tubes (IEC 61965:2003
ICS 31.120 Referenčna številka
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

EUROPEAN STANDARD EN 61965
NORME EUROPÉENNE
EUROPÄISCHE NORM October 2003

ICS 31.100 Supersedes EN 61965:2001

English version
Mechanical safety of cathode ray tubes
(IEC 61965:2003)
Sécurité mécanique  Mechanische Sicherheit
des tubes cathodiques von Kathodenstrahlröhren
(CEI 61965:2003) (IEC 61965:2003)

This European Standard was approved by CENELEC on 2003-10-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2003 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 61965:2003 E
Foreword
The text of document 39364/FDIS, future edition 2 of IEC 61965, prepared by IEC TC 39, Electronic
tubes, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61965
on 2003-10-01.
This European Standard supersedes EN 61965:2001.

The following dates were fixed:

– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2004-07-01

– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2006-10-01

The main change with respect to EN 61965:2001 is the inclusion of the requirements for cathode ray
tubes with film attached to the face plate.

Annexes designated "normative" are part of the body of the standard.
Annexes designated "informative" are given for information only.
In this standard, annex ZA is normative and annexes A and B are informative.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61965:2003 approved by CENELEC as a European Standard
without any modification.
__________
- 3 - EN 61965:2003
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any
of these publications apply to this European Standard only when incorporated in it by amendment or
revision. For undated references the latest edition of the publication referred to applies (including
amendments).
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 60065 (mod) 2001 Audio, video and similar electronic EN 60065 2002
apparatus - Safety requirements

IEC 60068-1 1988 Environmental testing
+ corr. October 1988 Part 1: General and guidance
+ A1 1992 EN 60068-1 1994
IEC 60216-1 2001 Electrical insulating materials - EN 60216-1 2001
Properties of thermal endurance
Part 1: Ageing procedures and
evaluation of test results
ISO 527-1 1993 Plastics - Determination of tensile
+ corr. 1 1994 properties EN ISO 527-1 1996
Part 1: General principles
ISO 527-3 1995 Part 3: Test conditions for films and EN ISO 527-3 1995
sheets
ISO 8510-1 1990 Adhesives - Peel test for a flexible- EN 28510-1 1993
bonded-to-rigid test specimen assembly
Part 1: 90 degree peel
INTERNATIONAL IEC
STANDARD
Second edition
2003-07
Mechanical safety of cathode ray tubes
Sécurité mécanique des tubes cathodiques
© IEC 2003 ⎯ Copyright - all rights reserved
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.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch  Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale
XA
International Electrotechnical Commission
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For price, see current catalogue

– 2 – 61965 © IEC:2003(E)
CONTENTS
FOREWORD . 5
INTRODUCTION .6
1 Scope . 7
2 Normative references. 7
3 Definitions . 8
4 General requirements . 9
4.1 Corrosion protection . 9
4.2 Mechanical damage. 9
4.3 Handling . 9
4.4 Film-coated CRTs. 9
5 Environmental conditioning .10
5.1 Standard atmospheric conditions for testing.10
5.2 Preconditioning.10
5.3 Thermal conditioning .10
6 Sampling .10
6.1 Sampling plans .10
6.2 Sample numbers.10
6.3 Compliance .10
7 Test preparation and set-up .10
7.1 Scratch patterns .10
7.2 Barriers .11
7.3 Mounting .11
7.4 Mounting position .11
8 Testing of large CRTs.11
8.1 Mechanical strength (ball impact test).11
8.2 Implosion test (missile) .12
8.3 Implosion test (thermal shock) .13
8.4 High-energy impact test.13
9 Testing of small CRTs.14
9.1 Mechanical strength (ball impact test).14
9.2 Implosion test (high ball).15
9.3 Implosion test (thermal shock) .15
9.4 High-energy impact test.15
10 Testing of prestressed banded CRTs with protective film .16
10.1 General .16
10.2 Film scoring pattern for CRTs with protective film .16
10.3 Peel test .17
10.4 Immersion test.17
11 Marking .17
12 Application notes for pre-stressed banded CRTs with protective film.18
13 Normative requirements for the use of Tables 1 and 2 (prestressed banded CRTs) .18
13.1 Sampling plan I: New construction .18
13.2 Sampling plan II: New construction with known resin or tape .19
13.3 Sampling plan III: Tension band and alternative tension band.19
13.4 Sampling plan IV: Alternative construction .20

61965 © IEC:2003(E) – 3 –
14 Normative requirements for the use of Tables 3 and 4 (prestressed banded with
protective film).21
14.1 Sampling plan I: New construction .21
14.2 Sampling plan II: New construction with known resin, tape, film or adhesive.22
14.3 Sampling plan III: Alternative tension band .22
14.4 Sampling plan IV: Alternative construction .23
15 Alternative thermal conditioning for use with Tables 3 and 4 (prestressed banded
with protective film).24
15.1 Additional peel force requirements where alternative thermal conditioning is
to be performed .24
15.2 Tensile strength test where alternative thermal conditioning is to be
performed.24
16 Normative requirements for the use of Tables 6 and 7 (bonded frame CRTs).25
16.1 Sampling plan I: New construction .25
16.2 Sampling plan II: Alternative construction .26
17 Normative requirements for the use of Tables 8 and 9 (laminated CRTs) .26
17.1 Sampling plan I: New construction .26
17.2 Sampling plan II: Alternative construction .26
Annex A (informative)  Background to the development of this standard.46
A.1 Mechanical strength test .47
A.2 Implosion test .47
A.3 Small CRTs (76 mm to 160 mm diagonal) .47
A.4 Evaluation time .47
Annex B (informative) Velocity and potential force of glass particles expelled from a
CRT subjected to a ball impact – Ballistic and statistical calculations .48
B.1 Introduction.48
B.2 Analysis without friction.48
B.3 Analysis with friction .54
B.4 Potential threat .57
B.5 Conclusions .57
Figure 1 – Example of a test cabinet .35
Figure 2 – Example of a ball impact test.36
Figure 3 – Example of a 2,3 kg steel missile .37
Figure 4 – Missile impact area on a typical CRT.38
Figure 5 – Example of a missile impact test.39
Figure 6 – Options for scratch patterns for implosions by the thermal shock method .40
Figure 7 – Film scoring tool.41
Figure 8 – Example of high-energy impact test set-up .42
Figure 9 – Steel pins used in high-energy impact test.43
Figure 10 –Weights used in high-energy impact test.44
Figure 11 – Example of 1,4 kg steel missile.45
Figure B.1 – Height of the barriers and distances from the CRT face.48

– 4 – 61965 © IEC:2003(E)
Figure B.2 – Example of the parabolic trajectory of a glass particle and the definition of
the distances.49
Figure B.3 – Definition of the initial angle and initial velocity and the forces acting on a
particle.50
Figure B.4 – Initial velocity required to pass over barriers at x = l (solid line) or x = l
1 2
(dashed line) as a function of the initial angle β.52
Figure B.5 – Trajectories for a glass particle for different initial angles and an initial
velocity of 4 m/s .52
Figure B.6 – Definition of the forces acting on a particle.54
Figure B.7 – Measurements of a typical glass particle .55
Figure B.8 – Trajectory of a glass particle with an initial velocity of 2 m/s and an initial
angle of 45° without friction (dashed line) and with friction (solid line) .56
Figure B.9 – Trajectories of a glass particle with an initial velocity of 2 m/s and an
initial angle of 45° for different values of the cross-sectional area .57
Table 1 – Sampling and test programme for prestressed banded CRTs exceeding
160 mm diagonal.27
Table 2 – Sampling and test programme for prestressed banded CRTs from 76 mm to
160 mm diagonal.28
Table 3 – Sampling and test programme for prestressed banded CRTs with protective
film exceeding 160 mm diagonal .29
Table 4 – Sampling and test programme for prestressed banded CRTs with protective
film from 76 mm to 160 mm diagonal.30
Table 5 – Sampling and test programme for adhesion of film used in CRTs with
protective film (tested according to Tables 3 and 4) .31
Table 6 – Sampling and test programme for bonded frame CRTs exceeding 160 mm
diagonal .32
Table 7 – Sampling and test programme for bonded frame CRTs from 76 mm to
160 mm diagonal.32
Table 8 – Sampling and test programme for laminated CRTs exceeding 160 mm
diagonal .33
Table 9 – Sampling and test programme for laminated CRTs from 76 mm to 160 mm
diagonal .33
Table 10 – CRT size and deflection angle ranges.34
Table B.1 – Values of the distances .49
Table B.2 – Upper and lower boundary values of the initial angle.51

61965 © IEC:2003(E) – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MECHANICAL SAFETY OF CATHODE RAY TUBES
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to
technical committees; any IEC National Committee interested in the subject dealt with may participate in this
preparatory work. International, governmental and non-governmental organizations liaising with the IEC also
participate in this preparation. IEC collaborates closely with the International Organization for Standardization
(ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between any
IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or other
damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising
out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61965 has been prepared by IEC technical committee 39:
Electronic tubes.
This second edition cancels and replaces the first edition published in 2000. This second
edition constitutes a technical revision.
The main change with respect to the previous edition is the inclusion of the requirements for
cathode ray tubes with film attached to the face plate.
The text of this standard is based on the following documents:
FDIS Report on voting
39/264/FDIS 39/265/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until 2005.
At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
– 6 – 61965 © IEC:2003(E)
INTRODUCTION
This International Standard sets forth test methods and limits for cathode ray tubes (CRTs).
Originally, the only IEC standard for the mechanical safety of CRTs had been contained within
Clause 18 of the equipment standard IEC 60065. Whereas that standard had been accepted
and used by many countries, many others were not able to implement its requirements
because of differing local needs. IEC 61965 was therefore published in 2000 with the aim of
providing the basis for wider acceptance and use and reflecting the current IEC policy of
producing separate component standards to which equipment standards can refer.
This 2nd edition covers the requirements for the CRTs with film attached to the faceplate as
part of the safety implosion protection system.
Many years of experience had been built up in the use of both the IEC 60065 test and the
other commonly used national alternatives. During the development of IEC 61965, extensive
test programmes and ballistic and statistical calculations were carried out to verify that the
requirements of the standard give protection for users of CRTs when the tubes are mounted
in the equipment for which they are intended. This was also done to ensure that IEC 61965
maintains the stringent requirements of both IEC 60065 and the alternative tests in common
use. These tests and calculations also confirmed
a) the acceptability of one standard ball for the mechanical strength test, and
b) the need for the implosion test where it is not always possible to induce rapid devacuation
using the ball impact test.
As the impact tests in this standard are overstress tests, only the effect of rapid devacuation
is evaluated and not subsequent relaxation of mechanical stresses in the CRT from the
implosion protection system.
61965 © IEC:2003(E) – 7 –
MECHANICAL SAFETY OF CATHODE RAY TUBES
1 Scope
This International Standard is applicable to cathode ray tubes and cathode ray tube
assemblies (hereinafter referred to as CRTs) which are intended for use as components in
apparatus and which have integral protection with respect to the effects of implosion.
These requirements apply to CRTs intended for use in apparatus including electrical and
electronic measuring and testing equipment, information technology equipment, medical
equipment, telephone equipment, television equipment and other similar electronic apparatus.
This standard is intended to apply only to those CRTs in which the face of the CRT forms part
of the enclosure for the apparatus. The test methods do not apply to CRTs which are
protected by separate safety screens.
A CRT covered by this standard is intended to be installed in an enclosure designed both to
protect the rear of the CRT against mechanical or other damage under normal conditions of
operation and to protect the user against particles expelled in a backwards direction from the
CRT face in the event of implosion.
This standard contains requirements for CRTs of 76 mm diagonal and larger that incorporate
implosion protection systems providing protection against the hazards of particles expelled
forwards beyond the face. There is no intended protection against particles expelled in other
directions.
Compliance is tested by subjecting CRTs to the test procedures and criteria, which are given
in Clauses 8 (large CRTs), 9 (small CRTs) and 10 (CRTs with protective film) of this standard.
The definitions of large and small CRTs are given in Clause 3.
NOTE This set of requirements replaces the current requirements for the mechanical safety of cathode ray tubes
(CRTs) as described in IEC 60065 (Clause 18), which will be modified accordingly.
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.
IEC 60065:2001, Audio, video and similar electronic apparatus – Safety requirements
IEC 60068-1:1988, Environmental testing – Part 1: General and guidance
Amendment 1 (1992)
IEC 60216-1:2001, Electrical insulating materials – Properties of thermal endurance – Part 1:
Ageing procedures and evaluation of test results
ISO 527-1:1993, Plastics – Determination of tensile properties – Part 1: General principles
ISO 527-3:1995, Plastics – Determination of tensile properties – Part 3: Test conditions for
films and sheets
ISO 8510-1:1990, Adhesives – Peel test for a flexible-bonded-to-rigid test specimen assembly
– Part 1: 90 degree peel
– 8 – 61965 © IEC:2003(E)
3 Definitions
For the purposes of this document the following definitions apply.
3.1
bonded frame
system employing a preformed metal frame that covers the periphery of the CRT rim area.
The space or void between the CRT rim and the metal frame is filled with resin or equivalent
3.2
CRT diagonal
nominal diagonal of the glass envelope at its maximum dimension (for example, mould-match
line) excluding any hardware
3.3
CRT envelope
structure consisting of a face or faceplate, funnel and neck assembly
3.4
devacuation
equalization of the pressure in a CRT relative to the ambient pressure
3.5
fracture
one or more cracks in the faceplate or funnel causing a rapid or slow devacuation of the
CRT envelope
3.6
glass particle
piece of glass that exceeds 0,025 g in weight
3.7
implosion
devacuation due to the rapid and sudden inward collapse of a CRT envelope, usually
accompanied by a loud report
3.8
laminated CRT
system that provides a separate external safety panel bonded to the face of the CRT
3.9
prestressed banded CRT
system that employs a metal tension band (located over the CRT rim area) that is tightened
by thermal shrinking, or other means, to a tensile load. The system may also include a metal
rim band located between the tension band and the CRT rim. The tension band or the rim
band or both may have an interlayer of tape, resin or the equivalent placed between the
mating parts
3.10
prestressed banded CRTs with protective film
system employing a prestressed banded construction (see 3.9) that also includes a layer of
film adhered to the CRT face as an integral component of the protection system

61965 © IEC:2003(E) – 9 –
3.11
shaling
condition where the glassware splits into thin layers
3.12
test cabinet
enclosure, which is used to accommodate the CRT during tests
3.13
useful phosphor screen
a) colour CRT: the visible phosphored area of the CRT as viewed from the front
b) monochrome CRT: specified maximum useful phosphored area of the CRT
3.14
large CRT
CRT with diagonal dimension exceeding 160 mm
3.15
small CRT
rectangular CRT with a minor face dimension of at least 50 mm, a minimum diagonal
dimension of 76 mm and a maximum diagonal dimension of 160 mm; a round CRT of a
minimum diameter of 76 mm and a maximum diameter of 160 mm
3.16
common quality management system
quality management system described in documentation which is identical with systems used
in two or more plants and under one central control and management
4 General requirements
4.1 Corrosion protection
If corrosion of a metal part will contribute to a failure to meet the requirements of this
standard, then the part shall be adequately protected against corrosion.
4.2 Mechanical damage
To improve repeatability and reproducibility of test results, it should be verified that samples
submitted for test have no external visible scratching on the surface of the faceplates.
4.3 Handling
Safety precautions should be addressed when handling test samples prior to and after testing.
4.4 Film-coated CRTs
In the case of CRTs with film, which is not an integral part of the implosion protection system,
the product must be tested without film in accordance with Tables 1 and 2 and 6 to 9.

– 10 – 61965 © IEC:2003(E)
5 Environmental conditioning
5.1 Standard atmospheric conditions for testing
Unless otherwise specified, all tests and measurements shall be made under standard
atmospheric conditions for testing as given in 5.3 of IEC 60068-1:
– temperature: 15 °C to 35 °C;
– relative humidity: 25 % to 75 %;
– air pressure: 86 kPa to 106 kPa
5.2 Preconditioning
Before CRTs are subjected to thermal conditioning or to testing they will be allowed to stabilize
at standard atmospheric conditions for testing (see 5.1) for a minimum period of 16 h.
5.3 Thermal conditioning
Details of thermal conditioning are given in Tables 1 to 9. After thermal conditioning has been
completed, the CRTs will be allowed to stabilize at standard atmospheric conditions for
testing (see 5.1) for a minimum period of 24 h.
6 Sampling
6.1 Sampling plans
Details are given in Tables 1 to 9.
6.2 Sample numbers
The numbers of CRTs and the test programmes for prestressed banded CRTs are given in
Tables 1, 2, 3 and 4, for bonded frame CRTs in Tables 6 and 7 and for laminated CRTs in
Tables 8 and 9.
NOTE 1 Additionally, the number of samples for film-adhesion testing are given in Table 5.
NOTE 2 In addition to the quantities specified in the tables, additional samples should be made available for use
in case of retest to satisfy the intent of the requirement.
6.3 Compliance
All CRTs in a test group shall comply with the test requirements for that group, except that, if
only one CRT from all the test groups does not comply with the requirements, acceptability
may be determined by subjecting a second test group to the set of tests during which
unacceptable results occurred. The construction is acceptable if all CRTs in the second test
group comply with the requirements.
7 Test preparation and set-up
7.1 Scratch patterns
As the form and depth of the scratch patterns may affect the force which is needed to obtain
implosion or devacuation of the CRT, it is recommended that the scratches be made using a
diamond- or carbide-tipped stylus, a glasscutter with a wheel of hardened steel or other
similar tools.
61965 © IEC:2003(E) – 11 –
7.2 Barriers
Barriers as specified in the test procedures, each made of 10 mm to 20 mm thick material,
250 mm high and (2,00 ± 0,01) m long, shall be placed on the floor in front of the test
−3
cabinet at the specified locations, measured horizontally from the vertical plane of the centre
of the front surface of the CRT to the near surface of the barrier closest to the tube face. The
tolerance on the position of the barrier shall be ±10 mm, unless otherwise stated. The barriers
may be less than 2 m long provided that they extend to the walls of the test room
(see Figures 2 and 5). A non-skid surface such as a blanket or rug may be placed on the
floor.
NOTE A particle travelling past the plane of the front surface of the barrier shall be considered to have passed
the barrier.
7.3 Mounting
The CRT shall be mounted in a test cabinet of rigid construction and of suitable dimensions
that does not permit a gap or opening wider than 6 mm around the CRT (see Figure 1).
The mounting of the CRT in front of, or behind, the front panel of the test cabinet shall be in
accordance with the CRT manufacturer's specifications or intended application. When
mounting specifications are not available, the preferred mounting method shall be behind the
front panel unless design features do not allow this condition.
A hole of suitable area shall be provided at the top of the cabinet to allow access to the
funnel. This hole shall be covered during the impact test.
An opening having an area of not less than one-quarter of the area of the face of the CRT
or 0,02 m , whichever is the smaller, shall also be provided in the bottom or rear of the
cabinet for air intake in the event of an implosion.
The cabinet shall be firmly supported so as to prevent movement during the test.
7.4 Mounting position
The centre of the CRT shall be (1,00 ± 0,05) m above the floor.
8 Testing of large CRTs
8.1 Mechanical strength (ball impact test)
8.1.1 Test procedure
A solid smooth steel ball of (40 ± 1) mm diameter and mass of (260 ± 15) g, including the
hook, and a minimum C scale Rockwell hardness of 60, shall be suspended by suitable
means such as a fine wire or chain with a mass not exceeding 10 % of the mass of the ball
and the hook. It shall be allowed to fall freely as a pendulum from a calculated height and
strike the face of the CRT with an energy of (5,5 ± 0,1) J. The CRT shall be placed so that the
face is vertical and in the same vertical plane as the point of support of the pendulum.
A single impact shall be applied to any point on the CRT face at a distance of 40 mm or
greater from the edge of the useful phosphor screen.
NOTE The test laboratory should consider all their test set-up uncertainties to ensure this 40 mm minimum
position of the point of impact.
The barrier shall be placed 1,5 m from the plane of the centre of the face of the CRT
(see Figure 2).
– 12 – 61965 © IEC:2003(E)
8.1.2 Glass throw criteria
A CRT is in compliance if the expulsion of glass within 5 s of the initial impact meets the
following requirements:
a) there shall be no glass particle (a single piece of glass having a mass greater than
0,025 g) past the 1,5 m barrier;
b) the total mass of all pieces of glass past the 1,5 m barrier shall not exceed 0,1 g.
8.2 Implosion test (missile)
8.2.1 Test procedure
The face of the CRT at the top and bottom shall be scratched (3 ± 1) mm from the screen or
phosphor edge into the viewing area. The scratches shall be horizontal lines (100 ± 5) mm long.
The impact object shall be a steel missile (see example in Figure 3) with a mass of (2,3 ± 0,1) kg,
a minimum C scale Rockwell hardness of 60 and having one end rounded on a radius of
(25 ± 0,5) mm.
The CRT shall be subjected to a single impact, intending to cause rapid devacuation using the
minimum energy within the range. The impact object shall be swung through an arc of a
pendulum to obtain an impact of not less than 7,0 J and not more than 14,0 J to cause rapid
devacuation of the samples in the test group.
The impact area shall be the area bounded by two concentric circles where the radius of one
circle is one-sixth of the height of the useful phosphor screen and the second circle radius is
one-half of the height of the useful phosphor screen less 50 mm (see Figure 4). In Figure 4, if
R is less than R then the impact shall be applied to the circle specified in R .
2 1 1
NOTE Previous testing experience on a particular CRT design (obtained from the CRT manufacturer or the test
laboratory) should be considered when selecting the energy level within the range and the impact location.
The impact object travel shall be restricted so that the rounded end of the missile penetrates
the CRT face equal to, or less than, 25 mm (see Figure 5).
Barriers shall be placed 1,0 m and 1,5 m from the vertical plane of the centre of the face of
the CRT (see Figure 5).
If no CRTs devacuate as a result of this test then the alternative implosion test (missile)
described in 8.2.3 shall be carried out.
8.2.2 Glass throw criteria
A CRT is in compliance if the expulsion of glass within 5 s of the initial impact meets the
following requirements:
a) there shall be no single piece of glass having a mass greater than 15 g between the 1,0 m
and 1,5 m barriers;
b) the total mass of all pieces of glass between the 1,0 m and 1,5 m barriers shall not exceed 45 g;
c) there shall be no single piece of glass having a mass greater than 1,5 g beyond the 1,5 m
barrier.
8.2.3 Alternative implosion test (missile)
This alternative test shall be used as an additional test when the test in 8.2.1 has devacuated
no CRTs, or may be used as an alternative to the test in 8.2.1 when it can be shown that
the 8.2.1 test is unlikely to devacuate at least one CRT of the sample group.

61965 © IEC:2003(E) – 13 –
8.2.3.1 Test procedure
As in 8.2.1, except that the impact object will be a steel missile (see example in Figure 11)
with a mass of (1,4 ± 0,1) kg, a minimum C scale Rockwell hardness of 60 and one end
rounded on a radius of (15 ± 0,5) mm.
8.2.3.2 Glass throw criteria
As in 8.2.2. If no CRTs devacuate as a result of the test in 8.2.3.1, then the glass throw
requirements of 8.2.2 are deemed to have been satisfied.
8.3 Implosion test (thermal shock)
8.3.1 Test procedure
The CRT shall be mounted in the test cabinet, which is described in 7.3 and 7.4. The barrier
shall be placed at (150 ± 2) mm from the vertical plane of the centre of the face of the CRT.
An area shall be scratched on the faceplate sidewall or face of the CRT using one of the
patterns illustrated in Figure 6.
A thermal shock shall be applied using one of the following methods.
a) Liquid nitrogen
The scratched area shall be cooled using liquid nitrogen until a fracture occurs. A dam of
modelling clay or equivalent may be used to contain the liquid nitrogen.
b) Hot rod
The end of an ordinary flint glass rod, of suitable diameter (for example, 10 mm) shall be
heated until it is red hot and nearly fluid. The heated end of the rod shall be pressed firmly
on the scratched area of the CRT. If devacuation of the CRT does not occur within 10 s
then the rod shall be withdrawn and cold water poured slowly on the scratched area. If a
devacuation cannot be induced by repeated applications of the hot rod then the test shall
be carried out using liquid nitrogen (see 8.3.1a).
8.3.2 Glass throw criteria
A CRT is in compliance if, within 5 s of the initial fracture, no glass particle is expelled through
the plane of the face beyond the 150 mm barrier.
8.4 High-energy impact test
CRTs, which have a laminated implosion protection system, shall be subjected to the
following high-energy impact test.
8.4.1 Test procedure
A (25 ± 1) mm diameter steel pin (see Figure 9) shall be inserted through the hole at the top
of the test cabinet and placed on the CRT envelope (3 ± 1) mm behind the seal of the
faceplate and funnel. If the hardware extends back from the seal more than 3 mm so as to
interfere with the placement of the pin, then the pin shall be placed as close as possible to the
hardware without touching it. A weight (see Figure 10), having a mass of (4,5 ± 0,1) kg, shall
be caused to fall from a height so as to impact the pin at the end of its fall.
The height of the test mass shall be adjusted to limit the amount of energy to the minimum
required to produce fracturing of the glassware, but not less than 7 J.
If fracturing of the glass does not occur, the impact energy shall be increased in 7 J
increments to a maximum of 63 J using a new test sample each time until all the CRTs in the
test group have suffered rapid devacuation.

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The impact energy shall not be so large as to cause the pin to punch a hole with little or no
cracking or shaling of the glassware. If this condition does occur then a lower impact energy
shall be selected so as to result in fracturing (7 J steps not necessary).
NOTE Previous testing experience on a particular CRT design (obtained from the CRT manufacturer or the test
laboratory) should be considered when selecting the energy level within the range.
The implosion pin shall be restricted so that its travel on impact shall be a maximum of 6 mm.
The pin travel restriction assembly shall be positioned so that its impact energy shall not be
transferred to the test cabinet. Figures 8, 9 and 10 give examples of equipment that may
be used.
Barriers shall be placed 1,0 m and 1,5 m from the plane of the centre of the face of the CRT.
8.4.2 Glass throw criteria
A CRT is in compliance if the expulsion of glass within 5 s of the initial impact meets the
following requirements:
a) there shall be no single piece of glass having a mass greater than 15 g between the 1,0 m
and 1,5 m barriers;
b) the total mass of all pieces of glass between the 1,0 m and 1,5 m barriers shall not exceed 45 g;
c) there shall be no single piece of glass having a mass greater than 1,5 g beyond the 1,5 m
barrier.
9 Testing of small CRTs
9.1 Mechanical strength (ball impact test)
9.1.1 Test procedure
A solid smooth steel ball of (40 ± 1) mm diameter and mass of (260 ± 15) g, including the
hook, and a minimum C scale Rockwell hardness of 60, shall be suspended by suitable
means such as a fine wire or chain with a mass not exceeding 10 % of the mass of the ball
and hook.
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