IEC TS 61496-4-2:2014

IEC TS 61496-4-2 ®
Edition 1.0 2014-06
TECHNICAL
SPECIFICATION
SPECIFICATION
TECHNIQUE
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 4-2: Particular requirements for equipment using vision based protective
devices (VBPD) – Additional requirements when using reference pattern
techniques (VBPDPP)
Sécurité des machines – Équipements de protection électro-sensibles –
Partie 4-2: Exigences particulières pour les équipements utilisant des dispositifs
protecteurs par vision (VBPD) – Exigences supplémentaires pour l'utilisation de
techniques de motifs de référence (VBPDPP)

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IEC TS 61496-4-2 ®
Edition 1.0 2014-06
TECHNICAL
SPECIFICATION
SPECIFICATION
TECHNIQUE
colour
inside
Safety of machinery – Electro-sensitive protective equipment –

Part 4-2: Particular requirements for equipment using vision based protective

devices (VBPD) – Additional requirements when using reference pattern

techniques (VBPDPP)
Sécurité des machines – Équipements de protection électro-sensibles –

Partie 4-2: Exigences particulières pour les équipements utilisant des

dispositifs protecteurs par vision (VBPD) – Exigences supplémentaires pour

l'utilisation de techniques de motifs de référence (VBPDPP)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX X
ICS 13.110; 29.260.99 ISBN 978-2-8322-1568-5

– 2 – IEC TS 61496-4-2:2014 © IEC 2014
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Functional, design and environmental requirements . 10
4.1 Functional requirements . 10
4.2 Design requirements . 12
4.3 Environmental requirements . 17
5 Testing . 19
5.1 General . 19
5.2 Functional tests . 19
5.3 Performance testing under fault conditions . 22
5.4 Environmental tests . 23
6 Marking for identification and for safe use . 31
6.1 General . 31
7 Accompanying documents. 31
Annex A (normative) Optional functions of the ESPE . 33
A.9 Setting the detection zone and/or other safety-related parameters . 33
A.9.1 Functional requirements . 33
A.9.2 Verification . 33
A.10 Selection of multiple detection zones . 34
A.10.1 Functional requirements . 34
A.10.2 Verification . 34
A.11 Automatic setting of detection zones . 35
A.11.1 Functional requirements . 35
A.11.2 Verification . 35
Annex B (normative) Catalogue of single faults affecting the electrical equipment of the
ESPE, to be applied as specified in 5.3 . 36
B.7 Imaging sensor . 36
Annex AA (informative) The positioning of VBPD in respect of parts of the human body . 37
AA.1 Calculation of distances for electro-sensitive protective equipment employing
vision based protective devices (VBPD) . 37
AA.2 Calculation of the overall minimum distance S . 37
o
AA.3 Vision based protective devices with a detection capability > 40 mm and ≤ 55
mm . 38
AA.4 Vision based protective devices with a detection capability > 55 mm and ≤
200 mm. 39
AA.5 Examples of detection zone and tolerance zone . 39
Bibliography . 44

Figure 1 – Image planes in VBPDPP . 9
Figure 2 – Side view of VBPDPP using a passive reference pattern . 11
Figure 3 – Light intensity measurement setup for indirect light tests . 28
Figure 4 – Light intensity measurement setup for direct light tests . 29

Figure AA.1 – Minimum distance S – Example 1 . 40
Figure AA.2 – Overall minimum distance S without tolerance zone – Example 1 . 40
o
Figure AA.3 – Overall minimum distance S including tolerance zone – Example 1. 41
o
Figure AA.4 – Minimum distance S – Example 2 . 41
Figure AA.5 – Overall minimum distance S without tolerance zone – Example 2 . 42
o
Figure AA.6 – Overall minimum distance S including tolerance zone – Example 2. 43
o
Table 1 – Verification of detection capability requirements (see also 4.2.12) . 20
Table 2 – Overview of light interference tests . 24

– 4 – IEC TS 61496-4-2:2014 © IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –

Part 4-2: Particular requirements for
equipment using vision based protective devices (VBPD) –
Additional requirements when using reference
pattern techniques (VBPDPP)
FOREWORD
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. In
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• the required support cannot be obtained for the publication of an International Standard,
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• the subject is still under technical development or where, for any other reason, there is the
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Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.

IEC/TS 61496-4-2, which is a technical specification, has been prepared by IEC technical
committee 44: Safety of machinery – Electrotechnical aspects.
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
44/677/DTS 44/689/RVC
Full information on the voting for the approval of this technical specification 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.
This part is to be used in conjunction with IEC 61496-1:2012.
This part supplements or modifies the corresponding clauses in IEC 61496-1:2012 to specify
particular requirements for the design, construction and testing of electro-sensitive protective
equipment (ESPE) for the safeguarding of machinery, employing vision based protective
devices (VBPD) using passive reference pattern techniques (VBPDPP) for the sensing
function.
Where a particular clause or subclause of Part 1 is not mentioned in this Part 4-2, 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.
Clauses and subclauses which are additional to those of Part 1 are numbered sequentially,
following on the last available number in Part 1.Terminological entries (in Clause 3) which are
additional to those in Part 1 are numbered starting from 3.4201. Additional annexes are
lettered from AA onwards.
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.

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.

– 6 – IEC TS 61496-4-2:2014 © IEC 2014
INTRODUCTION
An electro-sensitive protective equipment (ESPE) is applied to machinery presenting 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.
The working group responsible for drafting this technical specification 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 expertise is required. They considered that
if this high level of confidence could not be established these devices would not be suitable for
use in safety related applications.

SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –

Part 4-2: Particular requirements for
equipment using vision based protective devices (VBPD) –
Additional requirements when using reference
pattern techniques (VBPDPP)
1 Scope
Replacement:
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 vision-based protective devices (VBPDs) using passive
reference patterns (VBPDPP) 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 61496-1:2012 and this Technical Specification.
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.
A VBPDPP is defined as consisting of a single image-sensing device viewing on a passive
reference pattern as the background and where the detection principle is based on blocking or
partially preventing the view of the pattern. Information about the thickness, shape, surface
characteristics or location of the object is not required for detection. For multi-image sensing
devices, additional techniques, requirements and test procedures can be necessary.
• This part of IEC 61496 is limited to automatic vision-based ESPEs that do not require
human intervention for detection.
• It is limited to automatic vision-based ESPEs that detect objects entering into, or are
present in, a detection zone(s).
• It is limited to ESPEs using active illumination technique
• Excluded from this technical specfication are VBPDPPs employing radiation at wavelengths
outside the range 400 nm to 1 500 nm.
• This document does not address those aspects required for complex classification or
differentiation of the object detected.
This part of IEC 61496 is relevant for VBPDPPs having a stated detection capability up to
200 mm.
NOTE The positioning of VBPD in respect of parts of the human body is presented in Annex AA of this technical
specification.
This part of IEC 61496 does not deal with EMC emission requirements.
2 Normative references
Addition:
– 8 – IEC TS 61496-4-2:2014 © IEC 2014
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 62471:2006, Photobiological safety of lamps and lamp systems
ISO 13855:2010, Safety of machinery – Positioning of safeguards with respect to the approach
speeds of parts of the human body
ISO 20471:2013, High-visibility clothing – Test methods and requirements
3 Terms and definitions
Replacement:
3.3
detection capability
ability to detect the specified test pieces (see 4.2.13) in the specified detection zone
Note 1 to entry: Detection capability is generally measured by the size of object that can be detected. An increase
in detection capability means that a smaller object can be detected.
[SOURCE: IEC 61496-1:2012, 3.3, modified – text changed to make more relevant to vision
based sensors.]
Additions:
3.4201
image
snap shot representation of the scene in different planes of the VBPDPP in the form of a two
dimensional matrix
3.4202
imaging sensor
optoelectronic device which produces electrical signals representing the characteristics of an
image
3.4203
passive reference pattern
static (i.e. fixed location and not changing) regular (periodic) combination of pattern elements
on a background that covers at least the detection zone and the tolerance zone – blocking the
view of part of the pattern causes detection
Note 1 to entry: Regularity of the pattern refers only to the physical pattern and not to the image of the pattern as
seen by the imaging sensor.
3.4204
pattern element
local part of the passive pattern
EXAMPLE Black and white checker board – one black square or one white square.
3.4205
pixel,
smallest light sensitive element of an imaging sensor array

3.4206
pixel,
area of the smallest element that can be distinguished from its neighbouring elements
3.4207
sensing zone
three-dimensional volume defined by the field of view of the image sensor and with the apex at
the optical window of the sensor device
Note 1 to entry: The volume could be in the shape of a pyramid or cone.
Note 2 to entry: A zone of limited detection capability, a detection zone and tolerance zone(s) are contained within
the sensing zone. The zone of limited detection capability is located between the optical window of the sensor
device and the detection zone
3.4208
tolerance zone
zone outside of and adjacent to the (configured) detection zone within which the specified test
piece may not be detected
3.4209
vision-based protective device
VBPD
ESPE using an imaging sensor and active illumination, operating in the visible and near
infrared light spectrum to detect an object in a defined field of view
Note 1 to entry: This note applies to the French language only.
3.4210
vision-based protective device passive pattern
VBPDPP
VBPD using a single imaging device viewing on a passive reference pattern as background
Note 1 to entry: The various parts of a VBPDPP and their relationship to the viewed scene is shown in Figure 1.
Note 2 to entry: This note applies to the French language only.
Objective / lens
Imaging sensor
Data pre-
processing –
if applicable
Evaluation Image
reference pattern = scene Image in
sensor plane
IEC  1464/14
Figure 1 – Image planes in VBPDPP

– 10 – IEC TS 61496-4-2:2014 © IEC 2014
3.4211
zone with limited detection capability
volume between the detection zone and the optical window(s) of the sensing device which does
not achieve the stated detection capability
Note 1 to entry: The dimensions and appropriate information for use of the zone with limited detection capability
are provided by the supplier.
4 Functional, design and environmental requirements
This clause of Part 1 is applicable except as follows:
4.1 Functional requirements
4.1.1 Normal operation
This subclause of Part 1 is applicable.
4.1.2 Sensing function
Replacement:
4.1.2.1 General
The detection zone shall begin at the border of the zone of limited detection capability and end
at the passive pattern (see Figure 2).
NOTE It is possible that only parts of the passive pattern are used to define the detection zone.
Object(s) in the zone of limited detection capability shall not reduce the detection capability
within the detection zone. Any reduction of the detection capability shall be detected and the
VBPDPP shall go to lock-out condition (see 4.2.2.4).

sensing device
Zone with limited
detection capability
Optical
window
Tolerance zone
Tolerance zone
Background
(reference pattern)
Detection zone
IEC  1465/14
Figure 2 – Side view of VBPDPP using a passive reference pattern
4.1.2.2 Additional functional requirements
The sensing function shall be effective over the specified detection zone. No adjustment of the
detection zone or detection capability shall be possible without the use of a security measure
(e.g. key, key-word or tool).
The sensing device of a VBPDPP shall respond by giving (an) appropriate output signal(s)
when a test piece is placed anywhere within the detection zone either static or moving.
The supplier shall specify the limits of detection capability. The supplier shall take into account
worst case scenario including, for example, signal-to-noise ratio, light intensity in the image on
the sensor plane, contrast in the image on the sensor plane, position of the image on the
sensor, considering all influences listed in this part of IEC 61496.
4.1.2.3 Optical performance
The VBPDPP shall be designed and constructed to
a) limit the possibility of malfunction during exposure to extraneous radiation in the range of
400 nm to 1500 nm;
b) limit the effects of environmental influences (temperature, vibration and bumps, dust,
moisture, ambient light, extraneous reflections, changing illumination, shadows,
background reflectivity);
c) limit the misalignment at which normal operation is possible.
Operating distance
– 12 – IEC TS 61496-4-2:2014 © IEC 2014
4.1.3 Types of ESPE
Replacement:
In this technical specification, only a type 3 ESPE is considered. It is the responsibility of the
machine supplier and/or the user to determine if this type is suitable for a particular application.
The type 3 ESPE shall fulfill the fault detection requirements of 4.2.2.4 of this part of
IEC 61496. 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.
4.1.4 Types and required safety performance
This subclause of Part 1 is applicable.
or SIL and corresponding ESPE type
4.1.5 Required PL
r
This subclause of Part 1 is applicable.
New functional requirement:
4.1.6 Zone with limited detection capability
A zone between the optical window and the beginning of the detection zone is referred to as a
zone with limited detection capability. In order to ensure no hazard can arise in a particular
application due to the presence of this zone between the optical window and the detection
zone, its dimensions and appropriate information for use shall be provided by the supplier.
4.2 Design requirements
4.2.2 Fault detection requirements
4.2.2.2 Particular requirements for a type 1 ESPE
This subclause of Part 1 is not applicable.
4.2.2.3 Particular requirements for a type 2 ESPE
This subclause of Part 1 is not applicable.
4.2.2.4 Particular requirements for a type 3 ESPE
Replacement:
A single fault in the sensing device resulting in a complete loss of the stated VBPDPP detection
capability shall cause the ESPE to go to a lock-out condition within the specified response time.
A single fault resulting in a deterioration of the stated VBPDPP detection capability shall cause
the ESPE to go to a lock-out condition within a time period of 5 seconds following the
occurrence of that fault.
NOTE Examples of deterioration of the VBPDPP detection capability include:
– increase of the minimum detectable object size
– Increase in minimum detectable contrast
A single fault resulting in an increase in response time beyond the specified value or preventing
at least one OSSD going to the OFF-state shall cause the ESPE to go to a lockout condition

immediately, i.e. within the response time, or immediately upon any of the following demand
events where fault detection requires a change in state:
− on actuation of the sensing function;
− on switch off/on;
− on reset of the start interlock or the restart interlock, if available (see Clauses A.5 and A.6
of IEC 61496-1:2012).
It shall not be possible for the ESPE to achieve a reset from a lock-out condition, for example,
by interruption and restoration of the mains power supply or by any other means, when the fault
which initiated the lock-out condition is still present.
In cases where a single fault which does not cause a failure to danger of the ESPE is not
detected, the occurrence of one additional fault shall not cause a failure to danger.
For verification of this requirement, see 5.3.4.
4.2.2.5 Particular requirements for a type 4 ESPE
This subclause of Part 1 is not applicable.
NOTE Type 4 is not considered in this document. Additional definitions, requirements and test procedures would
be necessary.
Additional design requirements:
4.2.12 Integrity of the VBPDPP detection capability
4.2.12.1 General
The design of the VBPDPP shall ensure that the detection capability is not degraded below the
limits specified by the supplier and in this technical specification by any of, but not limited to,
the following:
a) at the minimum contrast between an object and reference pattern on the evaluation images;
NOTE Minimum contrast on the evaluation image can be achieved by low or high contrast in the scene.
b) the position of the object within the detection zone
c) the number of objects;
d) the size of objects;
e) auto-adjustment, for example the following:
1) auto-focus
2) gain control
3) orientation
4) sample rate
5) shutter time
6) aperture stops
7) focal length
f) properties/limitations of imaging sensor, for example the following:
1) signal noise (e.g. fixed pattern noise; dark noise)
2) dynamic range
3) sensitivity
4) micro lenses
5) gain settings
– 14 – IEC TS 61496-4-2:2014 © IEC 2014
6) cold and hot pixels
7) dark current
8) change of characteristics, e.g. wavelength dependent sensitivity, filter
9) photo response non-uniformity
g) accuracy of object position in images, accuracy and stability of calibration;
h) at the limits of alignment and/or adjustment;
i) ageing of components;
j) performance and limitations of the optical components;
k) component tolerances;
l) changing of internal and external references to guarantee the detection capability;
m) environmental conditions specified in 4.3.
If a single fault (as specified in Annex B of IEC 61496-1:2012), which under normal operating
conditions (see 5.1.2.1 of IEC 61496-1:2012) would not result in a loss of VBPDPP detection
capability but, when occurring with a combination of the conditions specified above, would
result in such a loss, that fault, together with that combination of conditions (as determined to
be relevant during the analysis of the design) shall be considered as a single fault and the
VBPDPP shall respond to such a single fault as required in 4.2.2.4.
The VBPDPP shall not fail to danger if a reflective object (for example, reflective clothes) is
placed at any position in the detection zone.
The relationship of the minimum detectable object size and the size of the elements of the
background pattern shall be sufficient to ensure the integrity of the detection capability (e.g.
object size is three or more times the size of the pattern element).
4.2.12.2 Detection zone
The supplier shall specify the size, shape and other relevant parameters of the detection
zone(s). The supplier shall define values in the range up to 200 mm as the minimum detectable
object size of the VBPDPP. The minimum detectable object size may be distance dependent.
All points on a path projected from any point on the border of the detection zone to the imaging
sensor of the VBPDPP shall be within the detection zone or the zone with limited detection
capability (see 4.1.4).
4.2.12.3 Response time
Objects of the minimum detectable size that are either stationary or moving within the detection
zone at any speed up to 1,6 m/s shall be detected by the ESPE within the specified response
time. The supplier shall specify the maximum response time. The supplier shall take into
account worst case conditions including, for example, frame rate, evaluation time, minimum
diameter of the test piece, maximum speed of the test piece and number of objects in the
detection zone as well as environmental influences. Where the supplier states that a VBPDPP
can be used to detect objects moving at speeds greater than 1,6 m/s, the requirements shall
be met at any speed up to and including the stated maximum speed(s).
4.2.12.4 Tolerance zone(s)
Where a tolerance zone is necessary, the supplier shall specify the tolerance zone(s).
The supplier shall take into account worst-case conditions including for example, signal-to-
noise ratio S/N.
NOTE The tolerance zone depends on optical performance, systematic interferences, pixel size, resolution,
geometry of the pattern elements, etc.

4.2.12.5 Passive reference pattern(s) and object discrimination
The reference pattern is part of the VBPDPP. The design of the passive reference pattern shall
be made in a way that discrimination of the object from the pattern can be achieved. The
detection capability shall not be decreased below the limits specified by the supplier by any of,
but not limited to the following influences:
a) contrast between pattern elements;
b) contrast changes within pattern elements;
c) size of pattern elements and number of pattern elements used for object detection;
d) size of pixels and numbers of pixels used for object detection;
e) algorithm/routines used for object discrimination in front of reference pattern;
f) automatical adaption of algorithm/routines;
g) size, shape, colour, reflectivity, position and texture of object compared to reference
pattern;
h) resulting contrast between object and pattern elements on the imaging sensor.
4.2.13 Test pieces for type testing
4.2.13.1 General
The test pieces shall be provided by the supplier for use in the type tests of Clause 5. They
shall be marked with a type reference and identification of the VBPDPP with which they are
intended to be used.
The test pieces shall be opaque.
The test pieces shall have a diameter equal to the maximum specified detection capability
(minimum diameter).
Different test pieces can be required for different phases of the test procedures.
Characteristics of the test piece which shall be considered are:
– size;
– shape;
– colour;
– reflectivity;
– contrast with background;
– texture.
When defining the characteristics of the test piece, protection against camouflage (i.e. mimic
the background appearance), with the reference pattern shall be taken into account. The
reflectivity of the test piece shall be selected to create a worst-case condition for the reference
pattern discriminators. As a minimum, the following surfaces shall be considered:
– A black surface with a diffuse reflectance value below 5 % at the operating wavelength of
the VBPDPP;
– a white surface with a diffuse reflectance value in the range of 80 % to 90 % at the
operating wavelength of the VBPDPP;
– a retroreflective surface that complies with the requirements for separate performance
retro-reflective material of ISO 20471 or equivalent.
Where other surface characteristics are shown to be critical as result of the analysis of the
design, these characteristics shall be applied to the test piece. Test pieces of different
reflectivity may be necessary.

– 16 – IEC TS 61496-4-2:2014 © IEC 2014
4.2.13.2 Spherical test piece
If the VBPDPP is intended to be used for whole body detection, then the test piece shall be a
sphere with a maximum diameter of 200 mm attached to a cylinder with a maximum diameter
of 50 mm and a length selected for ease of use.
NOTE A spherical test piece with a diameter of 200 mm is intended to represent the thickness of a body.
4.2.13.3 Cylindrical test piece
The test piece shall be cylindrical for detection capabilities up to 40 mm. The test piece shall
have a diameter equal to the maximum specified detection capability (minimum diameter) and
a length selected for ease of use.
NOTE Depending on the diameter of the cylindrical test piece, it can represent fingers, hands or wrists.
4.2.13.4 Conical test piece
The test piece shall be a truncated cone in combination with a cylinder if the VBPDPP is
intended to be used for arm detection. The test piece starts with a diameter of 40 mm
increasing up to 55 mm as a cone over a length of 180 mm and continues as a cylinder with a
diameter of 55 mm to an overall length of 440 mm.
The test piece shall be a truncated cone if the VBPDPP is intended to be used for leg
detection. The test piece starts with a diameter of 50 mm increasing up to 117 mm over a
length of 1 000 mm.
If the VBPDPP is intended to be used for detection of different parts of a body, the selection of
the most appropriate test pieces shall be dependent on the analysis of the design and intended
application. In some cases, all test pieces can be required.
4.2.14 Wavelength
VBPDPPs shall operate at a wavelength within the range 400 nm to 1 500 nm.
4.2.15 Radiation intensity
Where the VBPDPP is of the type that emits light and if the emitting device uses LED
technology, the radiation intensity generated and emitted by the VBPDPP shall meet the
requirements of exempt group in accordance to IEC 62471:2006.
NOTE Exempt group is equal to risk group zero (IEC 62471:2006).
Where the VBPDPP is of the type that emits light and if the emitting device uses laser
technology, the radiation intensity generated and emitted by the VBPDPP shall at no time
exceed the maximum power or energy levels for a class 1M device in accordance with 8.2 of
IEC 60825-1:2007.
4.2.16 Mechanical construction
When the detection capability can be decreased below the limit stated by the supplier as a
result of a change of position of its components, the fixing of those components shall not rely
solely on friction.
NOTE The use of oblong mounting holes without additional means could lead for example to a change of the
position of the detection zone under mechanical interference such as bump.

4.3 Environmental requirements
4.3.1 Ambient air temperature range and humidity
Addition:
The ESPE shall not fail to danger when subjected to a rapid change of temperature and
humidity leading to condensation on the optical window.
This requirement is verified by the condensing test of 5.4.2.
Additional environmental requirements:
4.3.5 Ambient light intensity
The VBPDPP shall continue in normal operation within a range of illumination on the passive
pattern, from 100 lx to 1 500 lx. If the supplier specifies background characteristics with lower
limits those shall be used. The tests shall be performed at those limits. Outside this range or
these limits the VBPDPP shall not fail to danger.
4.3.6 Light interference
The VBPDPP shall continue in normal operation when subjected to the following:
– incandescent light;
– flashing beacons;
– fluorescent lights operated with high-frequency electronic and line power supply.
The VBPDPP shall not fail to danger when subjected to
– incandescent light;
– stroboscopic light;
– high-intensity fluorescent lights operated with high-frequency electronic and line power
supply;
– laser beam;
– VBPDPP of identical design.
These requirements are verified by the tests of 5.4.6.
The supplier shall inform the user of potential problems not covered by the requirements of this
technical specification.
Based on the technologies and algorithms used as well as the analysis of 5.2.9, additional tests
may be necessary.
4.3.7 Pollution interference
4.3.7.1 Effects on optical window
Pollution on the optical window shall not lead to a failure to danger.
Pollution resulting in a complete loss of the stated VBPDPP detection capability shall
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