ISO 6742-2:2015

INTERNATIONAL ISO
STANDARD 6742-2
Third edition
2015-05-15
Cycles — Lighting and retro-
reflective devices —
Part 2:
Retro-reflective devices
Cycles — Dispositifs d’éclairage et dispositifs rétroréfléchissants —
Partie 2: Dispositifs rétroréfléchissants
Reference number
ISO 6742-2:2015(E)
©
ISO 2015

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ISO 6742-2:2015(E)

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ISO 6742-2:2015(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General . 2
4.1 Symbols and units used . 2
4.2 Chronological order of tests (only for reflectors) . 3
5 Photometrical requirements . 4
5.1 Reflectors . 4
5.2 Retro-reflective tyres . 6
5.3 Retro-reflective spokes or spoke cases . 7
6 Colorimetric requirements. 8
7 Physical requirements . 9
7.1 Reflectors . 9
7.1.1 Construction . 9
7.1.2 Test methods . 9
7.2 Retro-reflective tyres .10
7.2.1 Form and location .10
7.2.2 Test methods .10
7.3 Retro-reflective spokes or spoke cases .12
7.3.1 Construction .12
7.3.2 Test methods .12
8 Photometric test .13
8.1 General .13
8.1.1 Instrumentation arrangement .13
8.1.2 Source of illumination .14
8.1.3 Receiver .14
8.1.4 Observation distance.14
8.1.5 Illuminance at the reflector .14
8.2 Reflectors .14
8.2.1 Principle .14
8.2.2 Reflector mount (or support) .14
8.2.3 Test area of reflector .15
8.2.4 Orientation of reflector .15
8.3 Retro-reflective tyres .15
8.3.1 Principle .15
8.3.2 Test method .15
8.4 Retro-reflective spokes or spoke cases .15
8.4.1 Testing assemblies for retro-reflective spokes and spoke cases .15
8.4.2 Test method .16
9 Colorimetric test .16
9.1 Instrumental measurements .16
9.2 Visual comparison .17
9.3 Use of methods .17
10 Marking .17
Bibliography .18
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ISO 6742-2:2015(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on
the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT), see the following URL: Foreword — Supplementary information.
The committee responsible for this document is ISO/TC 149, Cycles, SC 1, Cycles and major sub-assemblies.
This third edition cancels and replaces the second edition (ISO 6742-2:1985), which has been
technically revised.
ISO 6742 consists of the following parts, under the general title Cycles — Lighting and retro-reflective devices:
— Part 1: Lighting and light signalling devices
— Part 2: Retro-reflective devices
— Part 3: Installation and use of lighting and retro-reflective devices
— Part 4: Lighting systems powered by the cycle’s movement
— Part 5: Lighting systems not powered by the cycle’s movement
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INTERNATIONAL STANDARD ISO 6742-2:2015(E)
Cycles — Lighting and retro-reflective devices —
Part 2:
Retro-reflective devices
1 Scope
This part of ISO 6742 is applicable to retro-reflective devices used on cycles intended to be used on
public roads and, especially, bicycles complying with ISO 4210 and ISO 8098.
This part of ISO 6742 specifies photometric and physical requirements of retro-reflective devices.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
CIE 15, Colorimetry: official recommendations of the International Commission on Illumination
CIE 1931, XYZ colour space of the International Commission on Illumination
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
retro-reflective device; reflector
assembly ready for use and comprising one or more retro-reflecting optical units
3.2
wide angle reflector
device providing retro-reflection through horizontal entrance angles of not less than 50° on either side
of the reference axis
3.3
conventional reflector
device providing retro-reflection through entrance angles of not less than 20° on either side of the
reference axis
3.4
high values reflector
red retro-reflective device with high values of reflection e.g. dedicated to be mounted on luggage carrier
3.5
retro-reflective spoke
spoke with retro-reflective surface
3.6
retro-reflective spoke case
device, e.g. cylinder, with retro-reflective surface with or without a gap, providing a secured
mounting on a spoke
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ISO 6742-2:2015(E)

3.7
retro-reflective tyre
tyre ready for use and comprising retro-reflecting annuli moulded on to each sidewall of the tyre
4 General
4.1 Symbols and units used
Symbols are shown in Figure 1. Their meaning and units used are given in Table 1.
Figure 1 — Symbols
NOTE The following symbols are in accordance with Regulation No.3 of the UN/ECE concerning retro-
reflective devices.
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ISO 6742-2:2015(E)

Table 1 — Meaning and units of symbols used
Symbol Meaning Unit
2
Α Area of the effective reflex surface of the retro-reflective device cm
C Reference centre —
NC Reference axis —
R Receiver, observer or measuring device —
r
C Centre of receiver —
R
Ø Diameter of receiver R , if circular cm
R r
S Source of illumination —
e
C Centre of source of illumination —
S
Ø Diameter of source of illumination cm
S
a
D Distance from centre C to centre C m
e S
a
D’ Distance from centre C to centre C m
e R
D Mean diameter of retro-reflective annulus on retro-reflective tyres mm
Degree and
α Observation angle
minutes
Entrance angle. With respect to line C C which always considered to be horizon-
S
tal, this angle is prefixed with signs – (left), + (right), + (up) or – (down), according
Degree and
β to the position of the source S in relation to the axis NC, as seen when looking
e
minutes
towards the retro-reflective device. For any direction defined by two angles, verti-
cal and horizontal, the vertical angle is always given first.
Degree and
γ Angular subtense of measuring device R , as seen from point C
r
minutes
Degree and
δ Angular subtense of the source S , as seen from point C
e
minutes
Rotation angle. This angle is positive when the rotation is clockwise as seen when
Degree and
ε looking towards the illuminated surface. If reflecting device is marked “TOP”, the
minutes
position thus indicated is taken as origin.
E Illuminance of retro-reflective device lux
millicandelas
CIL Coefficient of luminous intensity
per lux
a
D and D’ are generally very nearly the same and under normal conditions of observation it may be assumed that
e e
D = D’ . Furthermore, the effective distances may be used when a collimated system is used in order to obtain an artificially
e e
increased measuring distance.
4.2 Chronological order of tests (only for reflectors)
The applicant shall submit for approval samples which shall be tested in the chronological order
indicated in Table 2.
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ISO 6742-2:2015(E)

Table 2 — Chronological order of tests
Samples
Number of paragraph Tests for retro-reflective devices
a b c d e f
7.1.2.2 Temperature resistance test X X X X X X
Colorimetry: visual inspection
Clause 6 X X X X X X
Trichromatic coordinates in case of doubt
Clause 5 Photometry only at V = H = 0 ° X X X X X X
Clause 5 Photometry at all test points X X
7.1.2.4 Moisture resistance test X X
7.1.2.5 Resistance to fuels X X
7.1.2.6 Resistance to lubricating oils X X
Colorimetry: visual inspection
Clause 6 X X
Trichromatic coordinates in case of doubt
Clause5 Photometry only at V = H = 0 ° X X
Impact test
7.1.2.3 (only for wide angle reflector and conventional reflector X X
of Group B)
Colorimetry: visual inspection
Clause 6 X X
Trichromatic coordinates in case of doubt
Clause 5 Photometry only at V = H = 0 ° X X
5 Photometrical requirements
In order to follow different requirements in different countries, the photometrical requirements are
divided into 2 groups: Group A and Group B.
Table 3 — Tables link with groups
Group A Group B
Table 4 Table 5
Table 6 Table 7
Table 8 Table 9
Table 10 ―
Table 11 Table 12
Table 13 ―
Table 14 ―
NOTE Groups A or B have to be chosen according to national regulations.
5.1 Reflectors
When tested by the method given in Clause 8, the CIL values for reflectors shall not be less than those
specified in Tables 4, 5, 6, 7, 8, 9 or 10.
Tables 4 to 7 applies to front, side and rear reflectors.
Tables 8 and 9 applies to pedal reflectors.
Table 10 applies to high values reflectors. High values reflectors are only applicable in Group A.
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ISO 6742-2:2015(E)

Table 4 — Coefficients of luminous intensity, CIL, for conventional reflectors
Entrance angle β (in degree)
Observation
vertical V 0 ° ±10 ° ±5 °
Colour
angle α
horizontal H 0 ° 0 ° ±20 °
0 °20′ 1 200 800 400
White
1 °30′ 20 11,2 10
0 °20′ 750 500 250
Yellow
1 °30′ 12,5 7 6,25
0 °20′ 300 200 100
Red
1 °30′ 5 2,8 2,5
Table 5 — Coefficients of luminous intensity, CIL, for conventional reflectors
Entrance angle β (in degree)
Observation
Colour vertical V 0 ° ±10 ° 0 °
angle α
horizontal H 0 ° 0 ° ±20 °
0 °12′ 2 500 1 650 850
White
1 °30′ 26 18 11
0 °12′ 1 560 1 030 530
Yellow
1 °30′ 21 15 10
0 °12′ 625 410 210
Red
1 °30′ 9 6 4
Table 6 — Coefficients of luminous intensity, CIL, for wide angle reflectors
Entrance angle β (in degree)
Observation
Colour vertical V 0 ° ±10 ° 0 ° 0 ° 0 ° 0 °
angle α
horizontal H 0 ° 0 ° ±20 ° ±30 ° ±40 ° ±50 °
0 °20′ 1 800 1 200 610 540 470 400
White
1 °30′ 34 24 15 15 15 15
0 °20′ 1 125 750 380 335 290 250
Yellow
1 °30′ 21 15 10 10 10 10
0 °20′ 450 300 150 135 115 100
Red
1 °30′ 9 6 4 4 4 4
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ISO 6742-2:2015(E)

Table 7 — Coefficients of luminous intensity, CIL, for wide angle reflectors
Entrance angle β (in degree)
Observation
Colour vertical V 0 ° ±10 ° 0 ° 0 ° 0 ° 0 °
angle α
horizontal H 0 ° 0 ° ±20 ° ±30 ° ±40 ° ±50 °
0 °12′ 2 500 1 650 850 750 650 550
White
1 °30′ 26 18 11 11 11 11
0 °12′ 1 560 1 030 530 465 405 340
Yellow
1 °30′ 21 15 10 10 10 10
0 °12′ 625 410 210 185 160 135
Red
1 °30′ 9 6 4 4 4 4
Table 8 — Coefficients of luminous intensity, CIL, for pedal reflectors
Entrance angle β (in degree)
Observation
Colour vertical V 0 ° ±10 ° ±5 °
angle α
horizontal H 0 ° 0 ° ±20 °
0 °20′ 300 200 100
Yellow
1 °30′ 12 9 6
Table 9 — Coefficients of luminous intensity, CIL, for pedal reflectors
Entrance angle β (in degree)
Observation
Colour vertical V 0 ° ±10 ° 0 °
angle α
horizontal H 0 ° 0 ° ±20 °
0 °12′ 450 350 175
Yellow
1 °30′ 16,5 11,5 7,5
Table 10 — Coefficients of luminous intensity, CIL, for high values reflectors
Entrance angle β (in degree)
Observation
Colour vertical V 0 ° ±10 ° ±5 °
angle α
horizontal H 0 ° 0 ° ±20 °
0 °20′ 1 000 700 400
Red
1 °30′ 30 20 10
5.2 Retro-reflective tyres
When tested by the method given in Clause 8, the CIL values for a retro-reflective tyre shall not be less
those specified in Table 11 and Table 12. In case where D is less than 420 mm the minimum photometric
value for each observation and entrance angle shall be equal to the value for D = 420 mm
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ISO 6742-2:2015(E)

Table 11 — Coefficients of luminous intensity, CIL, for retro-reflective tyres
Observation Entrance angle β (in degree)
Colour
angle α horizontal H 5 ° 20 ° 40 ° 50 °
Either 0 °20′ 1,60 D 1,40 D 0,47 D 0,15 D
White
or
1 °30′ 0,11 D 0,10 D 0,065 D 0,020 D
White/Yellow
Table 12 — Coefficients of luminous intensity, CIL, for retro-reflective tyres
Observation Entrance angle β (in degree)
Colour
angle α horizontal H −4 ° 20 ° 40 ° 50 °
Either 0 °12′ 1,21 D 1,06 D 0,70 D 0,21 D
White
or
1 °30′ 0,121 D 0,106 D 0,070 D 0,021 D
White/Yellow
5.3 Retro-reflective spokes or spoke
...