SIST EN IEC 61496-3:2025

SLOVENSKI STANDARD
01-december-2025
Varnost strojev - Električno občutljiva zaščitna oprema - 3. del: Posebne zahteve
za aktivne optoelektronske zaščitne naprave, ki se odzivajo na difuzni odboj
(AOPDDR) (IEC 61496-3:2025)
Safety of machinery - Electro-sensitive protective equipment - Part 3: Particular
requirements for active opto-electronic protective devices responsive to diffuse reflection
(AOPDDR) (IEC 61496-3:2025)
Sicherheit von Maschinen - Berührungslos wirkende Schutzeinrichtungen - Teil 3:
Besondere Anforderungen an aktive optoelektronische diffuse Reflexion nutzende
Schutzeinrichtungen (AOPDDR) (IEC 61496-3:2025)
Sécurité des machines - équipements de protection électrosensibles - Partie 3:
Exigences particulières pour les équipements utilisant des dispositifs protecteurs
optoélectroniques actifs sensibles aux réflexions diffuses (AOPDDR) (IEC 61496-3:2025)
Ta slovenski standard je istoveten z: EN IEC 61496-3:2025
ICS:
13.110 Varnost strojev Safety of machinery
31.260 Optoelektronika, laserska Optoelectronics. Laser
oprema equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 61496-3

NORME EUROPÉENNE
EUROPÄISCHE NORM October 2025
ICS 13.110; 31.260 Supersedes EN IEC 61496-3:2019
English Version
Safety of machinery - Electro-sensitive protective equipment -
Part 3: Particular requirements for active opto-electronic
protective devices responsive to diffuse reflection (AOPDDR)
(IEC 61496-3:2025)
Sécurité des machines - Équipements de protection Sicherheit von Maschinen - Berührungslos wirkende
électrosensibles - Partie 3: Exigences particulières pour les Schutzeinrichtungen - Teil 3: Besondere Anforderungen an
équipements utilisant des dispositifs protecteurs aktive optoelektronische diffuse Reflexion nutzende
optoélectroniques actifs sensibles aux réflexions diffuses Schutzeinrichtungen (AOPDDR)
(AOPDDR) (IEC 61496-3:2025)
(IEC 61496-3:2025)
This European Standard was approved by CENELEC on 2025-09-18. 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 CEN-CENELEC
Management Centre 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 CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61496-3:2025 E

European foreword
The text of document 44/1061/FDIS, future edition 4 of IEC 61496-3, prepared by TC 44 "Safety of
machinery - Electrotechnical aspects" was submitted to the IEC-CENELEC parallel vote and approved
by CENELEC as EN IEC 61496-3:2025.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2026-10-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2028-10-31
document have to be withdrawn
This document supersedes EN IEC 61496-3:2019 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document is read in conjunction with EN IEC 61496-1:2020.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 61496-3:2025 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60068-2-64:2008 NOTE Approved as EN 60068-2-64:2008 (not modified)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Annex ZA of EN IEC 61496-1:2020, applies, except as follows:
Add:
Publication Year Title EN/HD Year
IEC 60068-2-14 2023 Environmental testing - Part 2-14: Tests - EN IEC 60068-2-14 2023
Test N: Change of temperature
IEC 60068-2-75 2014 Environmental testing - Part 2-75: Tests - EN 60068-2-75 2014
Test Eh: Hammer tests
IEC 60825-1 2014 Safety of laser products - Part 1: EN 60825-1 2014
Equipment classification and requirements
- - + A11 2021
- - + AC 2017-06
IEC 61496-1 2020 Safety of machinery - Electro-sensitive EN IEC 61496-1 2020
protective equipment - Part 1: General
requirements and tests
IEC 62471 (mod) 2006 Photobiological safety of lamps and lamp EN 62471 2008
systems
IEC/TS 62998-1 2019 Safety of machinery - Safety-related - -
sensors used for the protection of persons
IEC/TS 62998-3 2023 Safety of machinery - Safety-related - -
sensors used for the protection of persons
- Part 3: Sensor technologies and
algorithms
ISO 13855 2024 Safety of machinery - Positioning of EN ISO 13855 2024
safeguards with respect to the approach of
the human body
ISO 20471 2013 High visibility clothing - Test methods and EN ISO 20471 2013
requirements
IEC 61496-3 ®
Edition 4.0 2025-08
INTERNATIONAL
STANDARD
Safety of machinery - Electro-sensitive protective equipment -
Part 3: Particular requirements for active opto-electronic protective devices
responsive to diffuse reflection (AOPDDR)
ICS 13.110; 31.260 ISBN 978-2-8327-0593-3

IEC 61496-3:2025-08(en)
IEC 61496-3:2025 © IEC 2025
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 8
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions. 8
3.2 Abbreviated terms . 10
4 Functional, design and environmental requirements . 10
4.1 Functional requirements. 10
4.2 Design requirements . 11
4.3 Environmental requirements . 20
5 Testing . 24
5.1 General . 24
5.2 Functional tests . 25
5.3 Performance testing under fault conditions . 35
5.4 Environmental tests . 36
6 Marking for identification and for safe use . 54
6.1 General . 54
7 Accompanying documents . 54
Annex A (normative) Optional functions of the ESPE . 56
Annex B (normative) Catalogue of single faults affecting the electrical equipment of
the ESPE, to be applied as specified in 5.3 . 63
Annex AA (informative) Examples of the use of an AOPDDR in different applications . 64
AA.1 Positioning of AOPDDR-3D in respect of parts of the human body and
calculation of separation distances . 64
AA.1.1 General . 64
AA.1.2 Calculation of the overall separation distance S when reaching through
a vertical detection zone . 65
AA.1.3 AOPDDR-3D with a minimum detectable object size
40 mm < d ≤ 55 mm . 66
AA.1.4 AOPDDR-3D with a minimum detectable object size
55 mm < d ≤ 200 mm . 66
AA.1.5 Examples of detection zone and tolerance zone . 67
AA.1.6 Application examples for body detection of an AOPDDR-3D . 70
AA.2 Examples of the use of an AOPDDR . 72
AA.2.1 General . 72
AA.2.2 Limited distance . 72
AA.2.3 Overlap by the tolerance zone . 74
AA.2.4 Reference boundary monitoring . 75
AA.3 Detection zone angled to the direction of approach – Orthogonal approach . 76
AA.4 Example for the calculation of the response time of an AOPDDR-2D . 77
Annex BB (informative) Relationship between position accuracy and probability of
detection for a Type 3 AOPDDR . 78
Bibliography . 84

Figure 1 – Detection zone of an AOPDDR-2D . 15
IEC 61496-3:2025 © IEC 2025
Figure 2 – Detection zone of an AOPDDR-3D . 16
Figure 3 – Shape of test pieces for AOPDDR-3D . 18
Figure 4 – Minimum diffuse reflectivity of materials . 19
Figure 5 – Test piece intrusion into the detection zone for test . 26
Figure 6 – Influence on detection capability by incandescent light – Example 1 . 30
Figure 7 – Influence on detection capability by incandescent light – Example 2 . 31
Figure 8 – Influence on detection capability by light reflected by the background . 32
Figure 9 – Configuration for the endurance test – Example 1 . 33
Figure 10 – Configuration for the endurance test – Example 2 . 34
Figure 11 – Interference between two AOPDDR-3D of identical design (opposite
arrangement) . 44
Figure 12 – Interference between two AOPDDR-3D of identical design (parallel
arrangement) . 45
Figure 13 – Example of an emitting element of an AOPDDR . 47
Figure 14 – Example of a receiver of an AOPDDR . 47
Figure 15 – Influence on detection capability by background . 49
Figure 16 – Multi-path reflection test (top view) . 50
Figure 17 – Multi-path reflection test (side view) . 50
Figure A.1 – Reference boundary monitoring – Distribution of measurement values . 58
Figure A.2 – Use of an AOPDDR with reference boundary monitoring . 59
Figure A.3 – Use of an AOPDDR as parts of a body trip device. 60
Figure A.4 – AOPDDR used as a trip device with orthogonal approach (150 mm
minimum detectable object size) . 61
Figure A.5 – AOPDDR used as a trip device with orthogonal approach (200 mm
minimum detectable object size) . 62
Figure AA.1 – Separation distance S – Example 1 . 67
Figure AA.2 – Separation distance S including tolerance zone – Example 1 . 68
Figure AA.3 – Separation distance S – Example 2 . 69
Figure AA.4 – Separation distance S including tolerance zone – Example 2 . 70
Figure AA.5 – Application example for body detection of an AOPDDR-3D . 71
Figure AA.6 – Limited distance . 73
Figure AA.7 – Overlap . 74
Figure AA.8 – Reference boundary monitoring – Distribution of measurement values . 75
Figure AA.9 – AOPDDR-2D detection zone angled to the direction of approach –
Orthogonal approach . 76
Figure AA.10 – AOPDDR-3D detection zone angled to the direction of approach –
Orthogonal approach . 77
Figure BB.1 – Relationship between position accuracy and detection zone . 78
Figure BB.2 – Relationship between position accuracy, detection zone and the

probabilistic part of the tolerance zone – Example 1 . 79
Figure BB.3 – Relationship between position accuracy, detection zone and the
probabilistic part of the tolerance zone – Example 2 . 80
Figure BB.4 – Relationship between position accuracy, detection zone and tolerance
zone – Example 1 . 81
Figure BB.5 – Relationship between position accuracy, detection zone and tolerance

zone – Example 2 . 81
IEC 61496-3:2025 © IEC 2025
Figure BB.6 – POD of a single measurement (logarithmic) for a MooM-evaluation with
1 ≤ M ≤ 50 . 82
Figure BB.7 – POD of a single measurement for a MooM-evaluation with 1 ≤ M ≤ 50 in
relation to σ in the case of a normal distribution . 83

Table 1 – Minimum tests required for the verification of detection capability
requirements (see also 4.2.12.1) . 27
Table 2 – Overview of light interference tests . 39
Table B.1 – Sensor array for distance measurement . 63

IEC 61496-3:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Safety of machinery - Electro-sensitive protective equipment -
Part 3: Particular requirements for active opto-electronic protective
devices responsive to diffuse reflection (AOPDDR)

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,
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preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
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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
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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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 61496-3 has been prepared by IEC technical committee 44: Safety of machinery –
Electrotechnical aspects. It is an International Standard.
This fourth edition cancels and replaces the third edition published in 2018. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) some requirement clauses and test procedures have been adapted or removed because
they have been consolidated in IEC 61496-1:2020 (e.g. 5.4.6.2 Light sources and
Clause A.9);
b) change of the minimum probability of detection and fault detection requirements for Type 2
AOPDDR;
c) using the AOPDDR as a trip device is described as an optional function in Clause A.13.
IEC 61496-3:2025 © IEC 2025
The text of this International Standard is based on the following documents:
Draft Report on voting
44/1061/FDIS 44/1065/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
This document is to be used in conjunction with IEC 61496-1:2020.
The language used for the development of this International Standard is English.
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.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
This document supplements or modifies the corresponding clauses in IEC 61496-1:2020 to
specify 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 responsive to diffuse reflection (AOPDDR) for the sensing function.
Where a particular clause or subclause of IEC 61496-1:2020 is not mentioned in this document,
that clause or subclause applies as far as is reasonable. Where this document states "addition"
or "replacement", the relevant text of IEC 61496-1:2020 is adapted accordingly.
Clauses and subclauses which are additional to those of IEC 61496-1:2020 are numbered
sequentially, following on the last available number in IEC 61496-1:2020. Terminological entries
(in Clause 3) which are additional to those in IEC 61496-1:2020 are numbered starting from
3.301. Additional annexes are lettered from AA onwards.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
IEC 61496-3:2025 © IEC 2025
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 document supplements or modifies the corresponding clauses in IEC 61496-1:2020 to
specify 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 responsive to diffuse reflection (AOPDDRs) for the sensing
function.
Each type of machine presents its own particular hazards, and it is not the purpose of this
document to recommend the manner of application of the ESPE to any particular machine. The
application of the ESPE is 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, in IEC 62046 and ISO 12100.
The group responsible for drafting this document was concerned that, due to the complexity of
the technology, 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 experts is recommended. If this high level of confidence cannot
be established, these devices would not be suitable for use in safety related applications.

IEC 61496-3:2025 © IEC 2025
1 Scope
This document specifies additional requirements for the design, construction and testing of
non-contact electro-sensitive protective equipment (ESPE) designed specifically to detect
persons or parts of persons as part of a safety-related system, employing active opto-electronic
protective devices responsive to diffuse reflection (AOPDDRs) for the sensing function. Special
attention is directed to requirements which ensure that an appropriate safety-related
performance is achieved. An ESPE can include optional safety-related functions, the
requirements for which are given both in Annex A of this document and in Annex A of
IEC 61496-1:2020.
NOTE "Non-contact" means that physical contact is not required for sensing.
This document 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.
AOPDDRs are devices that have either
– one or more detection zone(s) specified in two dimensions (AOPDDR-2D), or
– one or more detection zone(s) specified in three dimensions (AOPDDR-3D)
wherein radiation in the near infrared range is emitted by an emitting element(s). When the
emitted radiation impinges on an object (for example, a person or part of a person), a portion
of the emitted radiation is reflected to a receiving element(s) by diffuse reflection. This reflection
is used to determine the position of the object.
Opto-electronic devices that perform only a single one-dimensional spot-like distance measure-
ment, for example, optical proximity switches, are not covered by this document.
This document is limited to ESPE that do not require human intervention for detection. It is
limited to ESPE that detect objects entering into or being present in a detection zone(s).
This document does not address those aspects required for complex classification or
differentiation of the object detected.
This document does not address requirements and tests for outdoor application.
Excluded from this document are AOPDDRs employing radiation with the peak of wavelength
outside the range 820 nm to 1 100 nm, and those employing radiation other than that generated
by the AOPDDR itself. For sensing devices that employ radiation of wavelengths outside this
range, this document can be used as a guide. This document is relevant for AOPDDRs having
a minimum detectable object size in the range from 30 mm to 200 mm.
This document can be relevant to applications other than those for the protection of persons,
for example, for the protection of machinery or products from mechanical damage. In those
applications, different requirements can be appropriate, for example when the materials that
are recognized by the sensing function have different properties from those of persons and their
clothing.
This document does not deal with electromagnetic compatibility (EMC) emission requirements.
IEC 61496-3:2025 © IEC 2025
2 Normative references
IEC 61496-1:2020, Clause 2 is applicable except as follows.
Addition:
IEC 60068-2-14:2023, Environmental testing - Part 2-14: Tests - Test N: Change of temperature
IEC 60068-2-75:2014, Environmental testing - Part 2-75: Tests - Test Eh: Hammer tests
IEC 60825-1:2014, Safety of laser products - Part 1: Equipment classification and requirements
IEC 61496-1:2020, Safety of machinery - Electro-sensitive protective equipment - Part 1:
General requirements and tests
IEC 62471:2006, Photobiological safety of lamps and lamp systems
IEC TS 62998-1:2019, Safety of machinery - Safety-related sensors used for the protection of
persons
IEC TS 62998-3:2023, Safety of machinery - Safety-related sensors used for the protection of
persons - Part 3: Sensor technologies and algorithms
ISO 13855:2024, Safety of machinery - Positioning of safeguards with respect to the approach
of the human body
ISO 20471:2013, High visibility clothing - Test methods and requirements
3 Terms and definitions
IEC 61496-1:2020, Clause 3 is applicable except as follows.
Replacement of the title with the following:
3 Terms, definitions and abbreviated terms
Addition:
3.1 Terms and definitions
Definition 3.1 is not applicable.
Replacement:
3.3
detection capability
ability to detect the specified test pieces in the specified detection zone
Note 1 to entry: A list of influences which can affect the AOPDDR detection capability is given in 4.2.12.1.
Note 2 to entry: Detection capability is often described by the minimum detectable object size and the object
reflectivity. The supplier can state more than one value as the minimum detectable object size, for example depending
on distances or mounting conditions. For an AOPPDR-2D the minimum detectable object size is the diameter of the
cylindrical test piece.
Note 3 to entry: A decrease of detection capability does not mean that a smaller object can be detected.
IEC 61496-3:2025 © IEC 2025
3.4
detection zone
zone within which the specified test piece(s) is detected by the AOPDDR with
a minimum required probability of detection
Note 1 to entry: A tolerance zone is necessary to achieve the required probability of detection of the specified test
piece(s) within the detection zone.
Addition:
3.301
active opto-electronic protective device responsive to diffuse reflection
AOPDDR
assembly using active optical radiation to detect the diffuse reflection of an object present in a
detection zone specified in two or three dimensions
3.302
AOPDDR-2D
AOPDDR that has one or more detection zone(s) specified in two dimensions
EXAMPLE A laser scanner that performs distance measurement by measuring the time a pulse needs for travelling
from the sensing device to an object and back to the sensing device. An AOPDDR-2D that has more than one
detection zone can carry out distance measurements in different planes.
Note 1 to entry: When the third dimension of each detection zone is not greater than the minimum detectable object
size, the AOPDDR is regarded as 2D.
3.303
AOPDDR-3D
AOPDDR that has one or more detection zone(s) specified in three dimensions
EXAMPLE A laser scanner with two perpendicular positioned moving mirrors or time-of-flight-cameras (TOF) that
perform distance measurement on several pixels. An AOPDDR-3D that has more than one detection zone can carry
out distance measurements in different volumes.
Note 1 to entry: When the third dimension of each detection zone is greater than the minimum detectable object
size, the AOPDDR is regarded as 3D. The detection zone(s) can be set-up for example as a volume in the shape of
a pyramid or a cone.
3.304
centre axis
line through the origin of distance measurement and the centre of the maximum detection zone
Note 1 to entry: See Figure 1 and Figure 2.
3.305
corner axis
line through the origin of distance measurement and defined by the bounding line of the
detection zone
Note 1 to entry: See Figure 1 and Figure 2.
3.306
maximum detection zone
largest dimension of the detection zone specified by the supplier
3.307
minimum detection zone
smallest dimension of the detection zone which is necessary to ensure the integrity of the
detection capability
IEC 61496-3:2025 © IEC 2025
3.308
position accuracy
accuracy in one or more dimension(s) of the position of an object as measured
3.309
tolerance zone
TZ
zone outside of and adjacent to the detection zone
Note 1 to entry: The tolerance zone is necessary to achieve the required probability of detection of the specified
test piece(s) within the detection zone
Note 2 to entry: For explanation of the concept of probability of detection and the tolerance zone, see Annex BB.
3.310
zone with limited detection capability
zone between the optical window and the beginning of the detection zone
Addition:
3.2 Abbreviated terms
AOPDDR active opto-electronic protective device responsive to diffuse reflection
BTD basic test distance
ESPE electro-sensitive protective equipment
lx Lux
OSSD output signal switching device
POD probability of detection
SNR signal-to-noise ratio
SRS/SRSS safety-related sensor / safety-related sensor system
TZ tolerance zone
4 Functional, design and environmental requirements
IEC 61496-1:2020, Clause 4 is applicable except as follows.
4.1 Functional requirements
4.1.2 Sensing function
Addition:
The detection zone shall begin at the border of the zone with limited detection capability and
end within the maximum operating distance.
Object(s) in the zone with limited detection capability shall not reduce the detection capability
within the detection zone. Any reduction of the detection capability shall be detected and the
AOPDDR shall go to lock-out condition.
The AOPDDR shall respond by giving appropriate output signal(s) when a test piece is present
anywhere within the detection zone whether static or moving with respect to the AOPDDR.
The supplier shall specify the limits of the detection capability. The supplier shall take into
account all influences listed in this document.
IEC 61496-3:2025 © IEC 2025
4.1.3 Types of ESPE
Replacement:
In this document, only type 2 and type 3 ESPE are considered. The types differ in their
performance in the presence of faults, under influences from environmental conditions and for
AOPDDR in the probability of detection. It is the responsibility of the machine supplier and/or
the user to specify which type is suitable for a particular application.
If IEC TS 62998-1 is applied in addition to this document (see e.g. 4.2.13.2), then the
requirements of SRS/SRSS performance class C for type 2 ESPE and SRS/SRSS performance
class D for type 3 ESPE shall be used.
The type 2 ESPE shall fulfil the fault detection requirements of 4.2.2.3 of this document. In
normal operation, the output circuit of each of at least two output signal switching devices
(OSSDs) shall go to the OFF-state when the sensing device is actuated, or when the power is
removed from the device.
The type 3 ESPE shall fulfil the fault detection requirements of 4.2.2.4 of this document. In
normal operation, the output circuit of each of at least two output signal switching devices
(OSSDs) of the type 3 ESPE shall go to the OFF-state when the sensing device is actuated, or
when the power is removed from the device.
When a single safety-related data interface is used to perform the functions of the OSSD(s),
then the data interface and associated safety-related communication interface shall meet the
requirements of 4.2.4.4. In this case, a single safety-related data interface can substitute for
two OSSDs in a type 3 ESPE.
Addition:
4.1.6 Zone(s) with limited detection capability
In order to ensure no hazard can arise in a particular application due to the presence of one or
more zone(s) with limited detection capability, the zone's dimensions and appropriate
information for use shall be provided by the supplier.
If the zone with limited detection capability extends more than 50 mm from the optical window
in the direction to the detection zone(s), then additional and effective technical measures shall
be applied to prevent undetected presence of objects or persons or parts of persons in the zone
with limited detection capability.
4.2 Design requirements
4.2.2 Fault detection requirements
4.2.2.2 Particular requirements for a type 1 ESPE
IEC 61496-1:2020, 4.2.2.2 is not applicable.
4.2.2.3 Particular requirements for a type 2 ESPE
Addition:
A single fault resulting in the deterioration of the stated AOPDDR detection capability shall
result in a lock-out condition at least as a result of the next periodic test. If the periodic test
cycle is less than 1 min then deterioration of the stated AOPDDR detection capability shall be
detected within 1 min.
IEC 61496-3:2025 © IEC 2025
EXAMPLE Deterioration of the AOPDDR detection capability includes:
– the increase of the minimum detectable object size,
– the increase in the minimum detectable reflectivity, and;
– the decrease of position accuracy.
If the periodic test is automatically initiated, the correct functioning of the periodic test shall be
monitored. In the event of a fault, the OSSD(s) shall be signalled to go to the OFF-state. If one
or more OSSDs do(es) not go to the OFF-state, a lock-out condition shall be initiated.
When it is not possible to reveal a failure to danger by periodic tests, other equivalent measures
shall be applied.
4.2.2.4 Particular requirements for a type 3 ESPE
Addition:
NOTE For AOPDDR using rotating mirrors for scanning the detection zone, this requirement can be fulfilled by
scanning on a defined reference object located outside the detection zone and the tolerance zone.
EXAMPLE Deterioration of the AOPDDR detection capability includes:
– the increase of the minimum detectable object size,
– the increase in the minimum detectable reflectivity, and
– the decrease of position accuracy.
An external test signal can be required if, for example, in a particular application, the frequency
of actuation of the sensing function is foreseeably low and the OSSDs are monitored at the
change of state only.
4.2.2.5 Particular requirements for a type 4 ESPE
IEC 61496-1:2020, 4.2.2.5 is not applicable.
4.2.12 Integrity of the ESPE detection capability
Replacement:
4.2.12.1 General
The design of the AOPDDR shall ensure that the detection capability is not decreased below
the limits specified by the supplier and in this document by any of, but not limited to, the
following:
a) reflectivity of objects in the range defined for the test pieces to be detected;
b) the position, size and number of objects within the detection zone;
c) the size of detection zones;
d) auto-adjustment, for example the following:
1) gain control;
2) sample rate;
3) shutter time;
4) optical characteristics;
IEC 61496-3:2025 © IEC 2025
e) properties and/or limitations of the emitting and/or receiving element, optics and signal
processing, for example the following:
1) signal noise;
2) dynamic range;
3) sensitivity and uniformity (e.g. cold and hot pixels);
4) micro-lenses;
5) change of characteristics;
f) calibration of the sensing device;
g) accuracy of object position in image(s);
h) at the limits of alignment and/or adjustment;
i) environmental conditions specified in 4.3;
j) component tolerances;
k) changing of characteristics of internal and external references to ensure the detection
capability.
NOTE 1 Under certain circumstances, limitations of the sensor in relation to its use are of interest. For example,
– objects that generate mirror-like (specular) reflections cannot be detected if the portion of diffuse reflectivity is
less than that specified for the "black" test piece;
– the determination of the minimum reflectivity for the detection of obstacles is based on the clothing of a person;
it is possible that objects having a reflectivity lower than that considered in this document are not detected.
NOTE 2 The technique of scanning on a reference object can satisfy the requirement in respect of ageing of
components. Other techniques giving the same level of assurance are possible.
NOTE 3 A receiving element can be composed of optics or optic-arrays and a single sensor element(s) or a sensor
array(s).
4.2.12.2 Detection zone(s) and tolerance zone(s)
The supplier shall specify the tolerance zone(s).
The supplier shall take into account worst-case conditions including, for example, signal-to-
noise ratio (SNR) and standard deviation σ considering all influences listed in this document
and any additional influences specified by the supplier (environmental influence, component
faults, multi-path reflections, etc.).
The supplier shall specify the relevant parameters of the detection zone(s), including operating
distance and scanning angle or field of view. The geometry and/or frequency shall be sufficient
to ensure that a test piece with a diameter of the specified minimum detectable object size is
detected at the maximum operating distance. The supplier shall specify values in the range of
30 mm to 200 mm as the minimum detectable object size of the AOPDDR. The minimum
detectable object size may be distance dependent.
The restriction of the minimum detectable ob
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