Safety of machinery - Electro-sensitive protective equipment - Part 2: Particular requirements for equipment using active opto-electronic protective devices (AOPDs)

IEC 61496-2:2013 specifies requirements for the design, construction and testing of electro-sensitive protective equipment (ESPE) designed specifically to detect persons as part of a safety-related system, employing active opto-electronic protective devices (AOPDs) for the sensing function. Special attention is directed to features which ensure that an appropriate safety-related performance is achieved. An ESPE may include optional safety-related functions, the requirements for which are given in Annex A of IEC 61946-1:2012 and of this part. This third edition cancels and replaces the second edition published in 2006. It constitutes a technical revision and includes the following significant technical changes with respect to the previous edition:
- Requirements have been corrected and made easier to understand.
- Test procedures have been revised to make them easier to perform and to improve repeatability.
- Guidance is provided for the evaluation and verification of AOPDs using design techniques for which the test procedures of this part are not sufficient.
This publication is to be read in conjunction with IEC 61496-1:2012.

Securité des machines - Equipements de protection électro-sensibles - Partie 2: Exigences particulières à un équipement utilisant des dispositif protecteurs optoélectroniques actifs (AOPD)

La CEI 61496-2:2013 définit les exigences de conception, de construction et d'essai d'équipements de protection électro-sensibles (ESPE) conçus spécialement pour détecter des personnes, comme partie d'un système relatif à la sécurité, utilisant des appareils protecteurs optoélectroniques actifs (AOPD) pour la fonction de détection. Une attention particulière est portée sur les caractéristiques assurant qu'une performance relative à la sécurité appropriée est atteinte. Un ESPE peut comporter des fonctions de sécurité optionnelles; les exigences pour ces fonctions sont données à l'Annexe A de la CEI 61946-1:2012 et de la présente Partie. Cette troisième édition annule et remplace la deuxième édition parue en 2006. Elle constitue une révision technique et inclut les modifications techniques majeures suivantes:
- Les exigences ont été corrigées et sont plus faciles à comprendre.
- Les méthodes d'essai ont été révisées pour être plus faciles à réaliser et pour améliorer la répétabilité.
- Des recommandations sont fournies pour l'évaluation et la vérification des appareils protecteurs optoélectroniques actifs (AOPD) utilisant des techniques de conception pour lesquelles les méthodes d'essai de la présente partie ne sont pas suffisantes.
Cette publication doit être lue conjointement avec l'IEC 61496-1:2012.

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Publication Date
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IEC 61496-2
Edition 3.0 2013-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 2: Particular requirements for equipment using active opto-electronic
protective devices (AOPDs)
Sécurité des machines – Équipements de protection électro-sensibles –
Partie 2: Exigences particulières à un équipement utilisant des appareils
protecteurs optoélectroniques actifs (AOPD)
IEC 61496-2:2013
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 61496-2
Edition 3.0 2013-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 2: Particular requirements for equipment using active opto-electronic
protective devices (AOPDs)
Sécurité des machines – Équipements de protection électro-sensibles –
Partie 2: Exigences particulières à un équipement utilisant des appareils
protecteurs optoélectroniques actifs (AOPD)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XA
ICS 13.110; 29.260.99 ISBN 978-2-83220-587-7

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – 61496-2 © IEC:2013
CONTENTS

FOREWORD ........................................................................................................................... 4

INTRODUCTION ..................................................................................................................... 6

1 Scope ............................................................................................................................... 7

2 Normative references ....................................................................................................... 7

3 Terms and definitions ....................................................................................................... 8

4 Functional, design and environmental requirements ......................................................... 9

4.1 Functional requirements .......................................................................................... 9

4.2 Design requirements ............................................................................................. 11

4.3 Environmental requirements .................................................................................. 14

5 Testing ........................................................................................................................... 14

5.1 General ................................................................................................................. 14

5.2 Functional tests ..................................................................................................... 17

5.4 Environmental tests ............................................................................................... 34

6 Marking for identification and safe use............................................................................ 42

6.1 General ................................................................................................................. 42

7 Accompanying documents .............................................................................................. 42

Annex A (normative) Optional functions of the ESPE ........................................................... 44

Annex B (normative) Catalogue of single faults affecting the electrical equipment of

the ESPE, to be applied as specified in 5.3 ........................................................................... 48

Annex AA (informative) Type 2 AOPD periodic test configurations ....................................... 49

Bibliography .......................................................................................................................... 51

Index .................................................................................................................................... 52

Figure 1 – Limit area for the protection against the risk of beam bypass ............................... 12

Figure 2 – Limit of vertical and horizontal misalignment ........................................................ 13

Figure 3 – Test piece at 45° .................................................................................................. 18

Figure 4 – Test piece at 90° .................................................................................................. 19

Figure 5 – Verifying sensing function by moving the test piece (TP) through the

detection zone near the emitter, near the receiver/retro-reflector target and at the

midpoint ................................................................................................................................ 19

Figure 6 – Limit values for the effective aperture angle (EAA) ............................................... 21

Figure 7 – Determination of the minimum detection capability ............................................... 22

Figure 8 – Measuring method for EAA (direction) .................................................................. 23

Figure 9 – Prism test to measure EAA of each beam ............................................................ 25

Figure 10 – EAA test using prism .......................................................................................... 26

Figure 11 – Design calculations for a wedge prism ............................................................... 27

Figure 12 – Example of optical subsystem: Emitter on left – Receiver on right ...................... 27

Figure 13 – Example of SMD LED Model .............................................................................. 28

Figure 14 – Example of intensity distribution of emitting element .......................................... 28

Figure 15 – Example of emitter model with beams internally blocked by aperture stop .......... 28

Figure 16 – Example of receiving unit with off axis beam portion reflected internally on

mechanical elements ............................................................................................................ 29

Figure 17 – Example of test piece inside model of optical subsystem with passing

radiation on the receiver ....................................................................................................... 30

---------------------- Page: 4 ----------------------
61496-2 © IEC:2013 – 3 –

Figure 18 – Example of emitting unit adjusted at the limit ...................................................... 31

Figure 19 – Extraneous reflection test with mirror outside of limit area .................................. 32

Figure 20 – AOPD misalignment test .................................................................................... 33

Figure 21 – Light interference test – Direct method ............................................................... 35

Figure 22 – Light interference test – Test set-up with incandescent light source ................... 36

Figure 23 – Light interference test – Test set-up with fluorescent light source ....................... 37

Figure 24 – Light interference test – Test set-up with flashing beacon light source ............... 38

Figure 25 – Light interference test – Test set-up with stroboscopic light source .................... 39

Figure AA.1 – Single beam sensing device ........................................................................... 49

Figure AA.2 – Series connection of single beam sensing devices ......................................... 49

Figure AA.3 – Assembly of multiple beams tested individually............................................... 49

Figure AA.4 – Example of type 2 AOPD with internal test ...................................................... 50

Table 1 – Correspondences of requirements/testing and AOPD designs ............................... 15

Table 2 – Maximum permissible angle of misalignment (in degrees) for a type 2 ESPE

depending on the dimensions of the light curtain ................................................................... 32

Table 3 – Maximum permissible angle of misalignment (in degrees) for a type 4 ESPE

depending on the dimensions of the light curtain ................................................................... 32

---------------------- Page: 5 ----------------------
– 4 – 61496-2 © IEC:2013
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –
Part 2: Particular requirements for equipment using
active opto-electronic protective devices (AOPDs)
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,

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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

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Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

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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

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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity

assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any

services carried out by independent certification bodies.

6) All users should ensure that they have the latest edition of this publication.

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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 61496-2 has been prepared by IEC technical committee 44: Safety

of machinery – Electrotechnical aspects, in collaboration with CENELEC technical committee

44X: Safety of machinery – Electrotechnical aspects.

This third edition cancels and replaces the second edition published in 2006. It constitutes a

technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:
a) Requirements have been corrected and made easier to understand.

b) Test procedures have been revised to make them easier to perform and to improve

repeatability.

c) Guidance is provided for the evaluation and verification of AOPDs using design

techniques for which the test procedures of this part are not sufficient.
---------------------- Page: 6 ----------------------
61496-2 © IEC:2013 – 5 –

This standard has the status of a product family standard and may be used as a normative

reference in a dedicated product standard for the safety of machinery.
This standard is to be used in conjunction with IEC 61496-1:2012.
This part supplements or modifies the corresponding clauses in IEC 61496-1.

Where a particular clause or subclause of Part 1 is not mentioned in this Part 2, that clause or

subclause applies as far as is reasonable. Where this part states "addition", "modification" or

"replacement", the relevant text of Part 1 is adapted accordingly.
The text of this standard is based on the following documents:
CDV Report on voting
44/651/CDV 44/670/RVC

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.

A list of all parts in the IEC 61496 series, published under the general title Safety of

machinery – Electro-sensitive protective equipment can be found on the IEC website.

The committee has decided that the contents of this publication will remain unchanged until

the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data

related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

that it contains colours which are considered to be useful for the correct

understanding of its contents. Users should therefore print this document using a

colour printer.
---------------------- Page: 7 ----------------------
– 6 – 61496-2 © IEC:2013
INTRODUCTION

Electro-sensitive protective equipment (ESPE) is applied to machinery that presents a risk of

personal injury. It provides protection by causing the machine to revert to a safe condition

before a person can be placed in a hazardous situation.

This part of IEC 61496 provides particular requirements for the design, construction and

testing of electro-sensitive protective equipment (ESPE) for the safeguarding of machinery,

employing active opto-electronic protective devices (AOPDs) for the sensing function.

Each type of machine presents its own particular hazards, and it is not the purpose of this

standard to recommend the manner of application of the ESPE to any particular machine. The

application of the ESPE should be a matter for agreement between the equipment supplier,

the machine user and the enforcing authority; in this context, attention is drawn to the relevant

guidance established internationally, for example, ISO 12100.

Due to the complexity of the technology of ESPEs there are many issues that are highly

dependent on analysis and expertise in specific test and measurement techniques. In order to

provide a high level of confidence, independent review by relevant expertise is recommended.

---------------------- Page: 8 ----------------------
61496-2 © IEC:2013 – 7 –
SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –
Part 2: Particular requirements for equipment using
active opto-electronic protective devices (AOPDs)
1 Scope
This clause of Part 1 is replaced by the following:

This part of IEC 61496 specifies requirements for the design, construction and testing of

electro-sensitive protective equipment (ESPE) designed specifically to detect persons as part

of a safety-related system, employing active opto-electronic protective devices (AOPDs) for

the sensing function. Special attention is directed to features which ensure that an

appropriate safety-related performance is achieved. An ESPE may include optional safety-

related functions, the requirements for which are given in Annex A of IEC 61946-1:2012 and

of this part.

This part of IEC 61496 does not specify the dimensions or configurations of the detection

zone and its disposition in relation to hazardous parts for any particular application, nor what

constitutes a hazardous state of any machine. It is restricted to the functioning of the ESPE

and how it interfaces with the machine.

Excluded from this part are AOPDs employing radiation at wavelengths outside the range

400 nm to 1500 nm.

This part of IEC 61496 may be relevant to applications other than those for the protection of

persons, for example, the protection of machinery or products from mechanical damage. In

those applications, additional requirements may be necessary, for example, when the

materials that are to be recognized by the sensing function have different properties from

those of persons.
This part does of IEC 61496 not deal with EMC emission requirements.
2 Normative references
This clause of Part 1 is applicable except as follows:
Additional references:

IEC 60825-1:2007, Safety of laser products – Part 1: Equipment classification and

requirements

IEC 61496-1:2012, Safety of machinery – Electro-sensitive protective equipment – Part 1:

General requirements and tests
IEC 62471, Photobiological safety of lamps and lamp systems

ISO 13855, Safety of machinery – Positioning of safeguards with respect to the approach

speeds of parts of the human body

EN 471:2003, High-visibility warning clothing for professional use – Test methods and

requirements.
---------------------- Page: 9 ----------------------
– 8 – 61496-2 © IEC:2013
3 Terms and definitions

NOTE At the end of this standard there is an index which lists, in alphabetical order, the terms and acronyms

defined in Clause 3 and indicates where they are used in the text.
This clause of Part 1 is applicable except as follows:
Additional definitions:
3.201
active opto-electronic protective device
AOPD

device whose sensing function is performed by opto-electronic emitting and receiving

elements detecting the interruption of optical radiations generated, within the device, by an

opaque object present in the specified detection zone (or for a light beam device, on the axis

of the light beam)
Note 1 to entry: This note applies to the French language only.
3.202
beam centre-line

optical path joining the optical centre of an emitting element to the optical centre of the

corresponding receiving element that is intended to respond to light from that emitting

element during normal operation

Note 1 to entry: The optical axis of a light beam is not always on the beam centre-line.

Note 2 to entry: Physical displacement of the beam centre-line may occur as a consequence of normal operation

(for example, by the use of a motor-driven mirror).

Note 3 to entry: For an AOPD that operates on a retro-reflective technique, the optical path is defined by the

retro-reflector target together with the emitting and receiving elements.
3.203
effective aperture angle
EAA

maximum angle of deviation from the optical alignment of the emitting element(s) and the

receiving element(s) within which the AOPD continues in normal operation
Note 1 to entry: This note applies to the French language only.
3.204
light beam device

AOPD comprising one or more emitting element(s) and corresponding receiving element(s),

where a detection zone is not specified by the supplier
3.205
light curtain

AOPD comprising an integrated assembly of one or more emitting element(s) and one or more

receiving element(s) forming a detection zone with a detection capability specified by the

supplier

Note 1 to entry: A light curtain with a large detection capability is sometimes referred to as a light grid.

3.206
test piece
opaque cylindrical element used to verify the detection capability of the AOPD
3.207
geometrically restricted optical design
GROD
AOPD using an optic design where
---------------------- Page: 10 ----------------------
61496-2 © IEC:2013 – 9 –

– the effective aperture angle (EAA) of each emitting and each receiving element does not

exceed the values given in Figure 6 and
– the axes of the optical beams are parallel and
– side lobes are minimized and
– the spacing between beam centre-lines is uniform and

– the value of detection capability is based on the complete obscuration of at least one

beam for any and all positions of the test piece within the detection zone (see Figure 7).

Note 1 to entry: This note applies to the French language only.
Replacement:
3.3
detection capability
dimension representing the diameter of the test piece which:

– for a light curtain, will actuate the sensing device when placed in the detection zone;

– for a single light beam device, will actuate the sensing device when placed in the beam

centre-line;

– for a multiple light beam device, will actuate the sensing device when placed in any beam

centre-line

Note 1 to entry: The term “detection capability” can also be used to mean the ability to detect a test piece of the

specified diameter.
4 Functional, design and environmental requirements
This clause of Part 1 is applicable except as follows:
4.1 Functional requirements
4.1.2 Sensing function
Replacement:
4.1.2.1 General requirements

The sensing function shall be effective over the detection zone specified by the supplier. No

adjustment of the detection zone, detection capability or blanking function shall be possible

without the use of a key, key-word or tool.

The sensing device of a light curtain shall be actuated and the OSSD(s) shall go to the OFF-

state when a test piece in accordance with 4.2.13 is placed anywhere within the detection

zone either static (at any angle) or moving (with the axis of the cylinder normal to the plane of

the detection zone), at any speed between 0 m/s and 1,6 m/s.

The sensing device of a light beam device shall be actuated and the OSSD(s) shall go to the

OFF-state when a test piece in accordance with 4.2.13 is present in the beam centre-line, at

any point throughout the operating distance, with the axis of the cylinder normal to the axis of

the beam.

NOTE The purpose of this requirement is to ensure that the OSSD(s) go to the OFF-state when a person or part

of a person passes through the detection zone or light beam. Based on a dimension of 150 mm and a walking

speed of 1,6 m/s, a minimum OFF time of 80 ms was determined to be adequate.

When the OSSD(s) go to the OFF-state, they shall remain in the OFF-state while the test

piece is present in the detection zone (or light beam) or for at least 80 ms, whichever is

greater.
---------------------- Page: 11 ----------------------
– 10 – 61496-2 © IEC:2013

Where the supplier states that an AOPD can be used to detect objects moving at speeds

greater than those specified above, the above requirements shall be met at any speed up to

and including the stated maximum speed(s).

4.1.2.2 Additional requirements for AOPDs using retro-reflective techniques and for

AOPDs using mixed emitters and receivers in the same assembly
4.1.2.2.1 General

AOPDs using retro-reflective techniques where the light beam traverses the detection zone

more than once (over the same path) and AOPDs using mixed emitters and receivers in the

same assembly shall not fail to danger if a reflective object (for example, reflective clothes) is

placed at any position in the detection zone.

NOTE The use of mirrors to return the light beam is not considered to be a retro-reflective technique.

4.1.2.2.2 Sensing function

The OSSD(s) shall go to the OFF-state when a reflective object of a size equal to, or greater

than, the diameter and length of the test piece (see 4.2.13) is placed in the detection zone at

any position as specified in 5.2.1.4.

For a type 4 AOPD, under normal operating conditions, the OSSD(s) shall go to the OFF-state

when a reflective object, as specified in 5.2.1.4 is placed as close as practicable in front of

the sensing surface of the emitting/receiving elements.
4.1.3 Types of ESPE
Replacement:

In this part of IEC 61496, only type 2 and type 4 ESPEs are considered. The types differ in

their performance in the presence of faults and under influences from environmental

conditions. In Part 1, the effects of electrical and electromechanical faults are considered

(such faults are listed in Annex B, Part 1). It is the responsibility of the machine manufacturer

and/or the user to determine which type is required for a particular appl
...

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