HIGHWAYS AGENCY
NETWORK CONTROL DIVISION
OPTICAL PERFORMANCE FUNCTIONAL
SPECIFICATION FOR DISCONTINUOUS
VARIABLE MESSAGE SIGNS
NOTE: This Specification is issued as an interim document for use until relevant European
Standards currently in preparation are published.
This document specifies performance requirements of products in accordance with current
practice of European standardisation activity.
© Crown Copyright 1995
Applications for reproduction should be made to HMSO.
first published 1995
Printed and published by the Highways Agency
TR 2136
Issue B
REGISTRATION OF AMENDMENTS
Amend
No
Page
No
November 1998
Signature & Date of
incorporation of
amendments
Amend
No
Page
No
Signature & Date of
incorporation of
amendments
i
TR 2136
Issue B
CONTENTS
EUROPEAN EQUIVALENCE CLAUSES
Page (iii)
1.
SCOPE
1
2.
INTRODUCTION
3
3.
APPLICATION
5
4.
DISPLAY REQUIREMENT
8
5.
OPTICAL PERFORMANCE
16
6.
TEST MODULES
25
7.
TEST AND CERTIFICATION REQUIREMENTS
28
8.
GLOSSARY OF TERMS
32
9.
REFERENCES
37
10.
HISTORY
39
APPENDIX 1, TEST PROCEDURES
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EUROPEAN EQUIVALENCE CLAUSES
1.
Any requirement of the specification for goods or materials to comply with a specified
standard shall be satisfied by compliance with:
(i)
a relevant standard or code of practice of a national standards body or equivalent
+
body of any Member State of the European Community ( European Economic
Area)
or
(ii)
any relevant international standard recognised for use in any Member State of the
+
European Community ( European Economic Area)
or
(iii)
a relevant specification acknowledged for use as a standard by a public authority of
+
any Member State of the European Community ( European Economic Area)
or
(iv)
traditional procedures of manufacture of a Member State of the European
+
Community ( European Economic Area) where these are the subject of a written
technical description sufficiently detailed to permit assessment of the goods or
materials for the use specified
or
(v)
a European Technical Approval (ETA) issued in accordance with the Construction
Products Directive 89/106/EEC (CPD)( or, until procedures are available for the
issue of ETAs, a specification sufficiently detailed to permit assessment) for goods
or materials of an innovative nature or subject to innovative processes of
manufacture and which fulfil the purpose provided for by the specified standard
provided that the proposed standard, code of practice, specification, technical
description or ETA provides, in use, levels of safety, suitability and fitness for
purpose equivalent to those required by the specified standard in so far as they are
not inconsistent with the Essential Requirements of the CPD.
2.
Any requirement of the specification to use material or an article which is defined by
reference to a named supplier or manufacturer shall be satisfied by using an equivalent
material or article of another manufacturer or supplier of any Member State of the
European Community, provided that this material or article is, in use, as safe, suitable and
fit for the relevant purpose as material or an article complying with the requirements set out
in the specification.
3.
Any requirement for any materials or articles to be designed, manufactured or supplied
subject to a quality management scheme or product certification scheme or approval
scheme shall be satisfied by compliance with any equivalent quality management scheme or
product certification scheme or approval scheme acknowledged for use by a public
authority of any Member State of the European Community provided that the scheme
ensures that the design, manufacture or supply offers, in use, equivalent levels of safety,
suitability and fitness for purpose.
November 1998
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TR 2136
4.
Issue B
+
Where testing is carried out in a Member State of the European Communities ( European
Economic Area), such tests shall be carried out by an appropriate organisation offering
suitable and satisfactory evidence of technical and professional competence and
independence. This condition shall be satisfied if the organisation is accredited in a Member
+
State of the European Communities ( European Economic Area) in accordance with the
relevant parts of the EN 45000 series of standards for the tests carried out.
+
{ Note that if the European Economic Area is ratified before publication, "European Communities"
in the text of the clause will be replaced by "European Economic Area" where shown}.
November 1998
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Issue B
SECTION 1
SCOPE
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Issue B
SECTION 1: SCOPE
1.1
This specification covers the optical requirements for all Discontinuous Variable Message
Signs (DVMS's) intended for use on public roads in England.
1.2
It defines mandatory requirement for:-
(a)
Optical Performance
(b)
Optical Test and Certification
1.3
Also included is an appendix detailing the necessary test procedures to demonstrate
compliance with the specification.
1.4
The majority of the content is related to the performance requirements but Table 1 and
some of the notes cover application issues related to ensuring Discontinuous Variable
Message Signs deliver the required performance on site. In these areas the information
supersedes that set out in TD 33/90 and TA 60/90. Some areas of guidance and warnings
of specific issues relating to light emitting technologies are contained but for advice please
contact:
HIGHWAYS AGENCY
TRAFFIC CONTROL SYSTEMS AND LIGHTING TEAM
ROOM 623
TOLLGATE HOUSE
HOULTON STREET
BRISTOL, BS2 9DJ.
Tel: 0117 987 8015
Fax: 0117987 8447
Email: ian.northam@highways.gov.uk
November 1998
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Issue B
SECTION 2
INTRODUCTION
November 1998
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Issue B
SECTION 2: INTRODUCTION
2.1
2.2
2.3
This specification describes all aspects of the optical requirements for discontinuous
variable message signs for use on trunk road motorways, trunk roads and other roads.
Any reference to "Signs" within this specification shall be taken to mean "Discontinuous
Variable Message Signs."
Discontinuous Variable Message Signs are those signs normally employing light emitting,
fluorescent, reflective or retro-reflective techniques whose legend/message characters
and/or symbols are made up from a series of spaced elements (as opposed to continuous
solid lines) and which are capable of displaying more than one message. It should be noted
that in this context, a blank face will normally be classified as a message condition.
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Issue B
SECTION 3
APPLICATION
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Issue B
SECTION 3: APPLICATION
3.1
Introduction
3.1.1 This section gives guidance for selection of the correct sign to be used for any given
application.
3.2
Sign Selection Criteria
3.2.1 Table 1 indicates the six permitted size ranges and the criteria for selection.
SIZE
RANGE
85 PERCENTILE
APPROACH
SPEEDS (MPH)
MAXIMUM NUMBER
OF WORDS IN
MESSAGE
MIN EQUIVALENT
CHARACTER
HEIGHT FOR ALL
APPLICATIONS (mm)
OPTICAL
PERFORMANCE
REQUIREMENTS
A
Up to and
including 30
3
60
1 or 2
B
Over 30 up to &
including 40
7
100
1 or 2
C
Over 40 up to &
including 50
7
160
1 or 2
D
Over 50 up to &
including 60
7
240
1
E1
Over 60
3
320
1
E2
Over 60
7
320
1
F
Over 60
7
400
1
Table 3.1
NOTES
1.
Size range E2 may only be used where the same message is repeated on two consecutive
signs
November 1998
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3.3
Issue B
Optical Performance Levels
3.3.1 There are 2 levels of optical performance applicable to Discontinuous Variable Message
Signs. The performance level required for any sign is dependent on its intended use.
3.3.2
Optical Performance Level 1 shall be required in the following cases:-
(a)
For all signs which are (or may be) required to display messages of a mandatory, safety or
warning nature.
(b)
For all signs necessitating a size range of D,E or F as required in paragraph 3.2.1.
3.3.3 Optical Performance Level 2 may be used for any signs in size ranges A to C inclusive when
not subject to the requirements of paragraph 3.3.2(a).
November 1998
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Issue B
SECTION 4
DISPLAY REQUIREMENT
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Issue B
SECTION 4: DISPLAY REQUIREMENT
4.1
Introduction
4.1.1 This section details the forms and dimensions of messages, legends and characters to be used
on Discontinuous Variable Message Signs.
4.2
Message and Legend Format
4.2.1 Messages shall conform to the standard list of prescribed messages as set out in legislation.
4.2.2 Legends conveying a message may comprise characters, symbols or a combination of the
two.
4.3 Characters shall be in upper case formed from matrices of a minimum of five horizontal
elements by seven vertical elements as shown by figures 4a and 4b.The character set shall be as set
out in TSRGD schedule 13 PartV, part 317.
4.4
Symbols
4.4.1 Any pictograms displayed by a VMS shall be within the range permitted by The Traffic Signs
Regulations and General Directions, (TSRGD).However, not all diagrams listed in the TSRGD are
suitable for light emitting technologies, therefore the acceptability of any pictogram proposed
should be agreed with the Type Approval Authority.
4.4.2 If a pictogram contains a red ring or triangle, Performance level 1 must be used.
4.4.3 Size spacing and position of the display elements of a pictogram shall be such that the image
displayed conforms to the dimensions and shape specified in the Working Drawings. The equivalent
area of the display elements shall not extend beyond the area delineated by the Working Drawing of
the equivalent plate sign.
4.4.4 The test module defined in 6.2.2 shall represent the element size and spacing chosen by the
manufacturer to conform to 4.3
November 1998
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Issue B
REGULAR MATRIX - LIGHT EMITTING
A
B
C
A = Element spacing
B = Element diameter
C = Equivalent diameter or stroke width
Figure 4a
November 1998
Traffic Systems & Signing
Drawing Office No. 2401
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Issue B
REGULAR MATRIX - NON LIGHT EMITTING
A
A = Element diameter or stroke width
Figure 4b
Traffic Systems & Signing
Drawing Office No. 2401
November 1998
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4.5
Issue B
Character/Legend Dimensions
4.5.1 Minimum dimensions and spacing of legend and related components of discontinuous variable
message signs shall be defined in Table 4.1, fig 4c and fig 4d..
MINIMUM DIMENSIONS
MINIMUM
MINIMUM MINIMUM
SIZE
MINIMUM
CHARACTER WORD
RANGE CHARACTER STROKE
SPACING
SPACING
WIDTH
HEIGHT
(mm)
(mm)
(mm)
(mm)
MINIMUM
LINE
SPACING
(mm)
MINIMUM
WIDTH OF
BORDER
(mm)
A
60
9
18
45
36
60
B
100
14
28
70
56
100
C
160
23
46
115
92
160
D
240
34
68
170
136
240
E
320
46
92
230
184
320
F
400
57
114
285
228
400
Table 4.1
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Issue B
LEGEND MINIMUM SPACINGS
A
B
C
D
A = Character height with equivalent area
(stroke width x number of vertical elements).
B = Character spacing (stroke width x 2).
C = Word spacing (stroke width x 5).
D = Line spacing (stroke width x 4).
E = Character width with equivalent area
(stroke width x number of horizontal
elements).
E
NOTE
1. Dotted area around each element represents
the equivalent area.
Figure 4c
Traffic Systems & Signing
Drawing Office No. 2401
November 1998
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TR 2136
Issue B
BORDERS
Shows A with
equivalent area
A
>he
ABC
he
>he
>he
>he
he = Equivalent character height.
Figure 4d
Traffic Systems & Signing
Drawing Office No. 2401
November 1998
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4.6
Issue B
Sign Intensity Control
4.6.1 The intensity of the legends and conspicuity devices displayed by the sign shall be variable to
compensate for all ambient light levels.
4.6.2 Although testing of the intensity control is beyond the scope of this document the
performance of the sign operating under this dimming control must meet values specified in tables
5.1 and table 5.4.
4.7
Conspicuity Devices
4.7.1 Flashing amber lanterns shall be used with signs displaying messages of a mandatory, safety or
warning nature.
4.7.2 The colour of amber lanterns shall be within the boundaries of yellow defined by the colour
chart for signs to optical performance level 1 as given in paragraph 5.5.5. The on axis luminous
intensity shall be between 400 and 800 candelas.
4.7.3 The proportion of conspicuity devices should relate to the size of the sign. The diameter of
conspicuity devices shall not be less than 50% of equivalent character height of the sign or 100mm
which ever is the greater.
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Issue B
SECTION 5
OPTICAL PERFORMANCE
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Issue B
SECTION 5 : OPTICAL PERFORMANCE
5.1
Introduction
5.1.1 This section outlines the optical performance requirements for all Discontinuous Variable
Message Signs to be used on public roads in England.
5.1.2 Test procedures to prove compliance are given in Appendix 1.
5.2
General Requirements
5.2.1 The optical performance outlined in this specification shall be assessed and certified by a
NAMAS accredited optical test house in accordance with Section 7. This shall be a mandatory
requirement for suppliers seeking Statutory Type Approval or proposing installation on Highways
Agency roads.
5.2.2 All tests and certification shall be carried out using Test Modules provided by the Supplier
and manufactured in accordance with Section 6.
5.2.3 Unless otherwise stated, all optical performance tests shall be carried out on the test module
geometric axis.
5.2.4 The prescribed luminance ratio requirements shall be achieved with the appropriate sign
dimming levels activated, as notified by the supplier.
5.2.5 The levels of optical performance are as described in paragraph 3.3.
5.2.6 Optical Performance shall be assessed and certificated according to the Performance level(s)
requested by the supplier in the functional specification.
5.2.7 When tested in accordance with Appendix 1, results shall be achieved within the specified
limits.
5.2.8 Certification to this specification shall be required under each of the following headings, and
for each performance level requested by the supplier:(a)
(b)
(c)
(d)
(e)
Luminance Ratio
Luminance Levels
Viewing Angle (Luminance Ratio)
Luminous Intensity Uniformity
Colours
5.3
OPTICAL PERFORMANCE LEVEL 1
5.3.1
Luminance Ratio
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Issue B
5.3.1.1 The acceptable limits of Luminance Ratio shall be as defined in Table 5.1.
LIMITS OF LUMINANCE RATIO AND LUMINANCE
Performance 1
(White,Yellow,White/Yellow)
Sign
Illuminance
(Lux)
Minimum
Luminance
ratio LR
Performance 1
(Red,Green,Blue)
Luminance
(cd/m2)
Minimum
luminance
ratio LR
*Minimum
Maximum
Luminance
(cd/m2)
*Minimum Maximum
40,000
10
6,200
120,000
5
2,800
60,000
4,000
10
1,100
21,000
5
500
10,000
400
10
300
3,700
5
200
2,700
40
-
200
2,000
-
100
2,000
<4
-
60
300
-
60
300
Table 5.1
Note(*) The values of luminance given have to be achieved with the sign set to achieve the
indicated Luminance ratio requirements but are measured with the solar simulator turned off.
5.3.2
Luminance
5.3.2.1 Levels of Luminance shall be as indicated in Table 5.1 when measured under laboratory
conditions. When more than one colour is used then the luminance levels of all the colours shall be
balanced and related to a single reference level, which shall be white. Therefore, yellow will be ½
the luminance level of white; red ¼; green 1/5; and blue1/6. These measurements shall be within
±25%.
5.3.3
Viewing Angle Luminance Ratio
5.3.3.1 There will be two separate requirements for viewing angle.
5.3.3.1.1 Narrow Beam (Level N) = ± 5° horizontal and -2.5° vertical.
5.3.3.1.2 Wide Beam (Level W) = ± 10° horizontal and -2.5° vertical.
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Issue B
PERFORMANCE 1 VIEWING ANGLE - LUMINANCE RATIO REQUIREMENT
Sign illuminance
(Lx)
Minimum Luminance Ratio (LR)
Performance 1
White, Yellow
White/Yellow
Performance 1
Red
Green, Blue
40,000
5
3
<4
5
3
Table 5.2
COMBINED UNIFORMITY TEST POINTS FOR EACH ELEMENT
Narrow Beam (Level N)
Wide Beam (Level W)
Horizontal
Vertical
Horizontal
Vertical
-3°
-2°
-7°
-2°
+3°
-2°
+7°
-2°
0°
0°
0°
0°
Table 5.3
5.3.4
Luminous Intensity Uniformity
5.3.4.1 The luminous intensity uniformity, shall be separately met for each colour.
5.3.4.2 When measured on axis and at the combined angles, as table 5.3, for a narrow or wide
beam without external illuminance, the ratio of the average of the highest 3 element outputs to the
average of the lowest 3 element outputs shall not exceed 2.5:1.
5.3.4.3 When measured as above the ratio of the outputs of any two elements shall not exceed 5:1.
November 1998
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5.3.5
Issue B
Colours
5.3.5.1 For signs optical performance level 1:(a)
(b)
Character legends shall only be white, white/yellow or yellow.
Symbol colours shall be as authorised in the current version of The Traffic Signs
Regulations and General Directions.
5.3.5.2 When measured with the test module fully dimmed on axis and at the appropriate horizontal
and vertical viewing angles defined in 5.3.3, colour co-ordinates shall be within the limits given in
table 5.4 and as shown in Fig 5a.
COLOUR CO-ORDINATES FOR SIGN OPTICAL PERFORMANCE
LEVEL 1 and 2
1
2
3
4
Red
x
y
0.690
0.290
0.710
0.290
0.680
0.320
0.660
0.320
Yellow
x
y
0.536
0.445
0.545
0.454
0.592
0.407
0.583
0.398
Yellow*
(when used in
conjunction
with Red )
x
y
0.560
0.440
0.440
0.382
0.285
0.264
0.285
0.332
Green
x
y
0.009
0.720
0.284
0.520
0.207
0.397
0.012
0.494
Blue
x
y
0.090
0.137
0.186
0.214
0.233
0.167
0.148
0.025
White
x
y
0.440
0.382
0.285
0.264
0.285
0.332
0.440
0.432
White/Yellow**
x
y
0.618
0.382
0.440
0.382
0.285
0.264
0.285
0.332
5
0.490
0.510
0.490
0.510
Table 5.4
* These co-ordinates for yellow apply when yellow is used in conjunction with red on the same
sign face.
** Where both of the colours white and yellow are used together upon the sign face, then those
colours shall be within the limits individually specified for those colours. The combined
White/Yellow boundary is specified for those signs where colour separation between white and
yellow is not required, i.e. those signs, which may be white , off white or yellow.
November 1998
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Issue B
FIG 5a
November 1998
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Issue B
5.4 OPTICAL PERFORMANCE LEVEL 2
5.4.1 Luminance Ratio
5.4.1.1. The acceptable limits of Luminance Ratio shall be as defined in Table 5.5.
LIMITS OF LUMINANCE RATIO AND LUMINANCE
Sign
Illuminance
(Lux)
Performance 2
(White,Yellow,White/Yellow)
Minimum
Luminance ratio
LR
Performance 2
(Red,Green,Blue)
Luminance
2
(cd/m )
Minimum
luminance
ratio LR
*Minimum
Maximum
Luminance
2
(cd/m )
*Minimum
Maximum
40,000
5
3,100
120,000
3
1,550
60,000
4,000
5
550
21,000
3
225
10,000
400
5
150
3,700
3
100
2,700
40
-
100
2,000
-
50
2,000
<4
-
30
300
-
30
300
Table 5.5
Note:(*) The values of luminance given have to be achieved with the sign set to achieve the
indicated Luminance ratio requirements but are measured with the solar simulator turned off.
November 1998
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Issue B
5.4.2 Luminance
5.4.2.1 Levels of Luminance shall be as indicated in Table 5.5 when measured under laboratory
conditions. When more than one colour is used then the luminance levels of all the colours shall be
balanced and related to a single reference level, which shall be white. Therefore, yellow will be ½
the luminance level of white; red ¼; green 1/5; and blue1/6. These measurements shall be within
±25%.
5.4.3 Viewing Angle Luminance Ratio
5.4.3.1 There are two separate requirements for viewing angle.
5.4.3.1.1 Narrow Beam (Level N) = ± 5° horizontal and -2.5° vertical.
5.4.3.1.2 Wide Beam (Level W) = ± 10° horizontal and -2.5° vertical.
5.4.3.2 For performance 2 certification a minimum luminance ratio of 3:1 shall be obtained for all
colours as Table 5.6.
PERFORMANCE 2 VIEWING ANGLE-LUMINANCE RATIO REQUIREMENT
Sign Illuminance (Lux)
Performance 2 Minimum Luminance Ratio
(LR)
40,000
3
<4
3
Table 5.6
COMBINED UNIFORMITY TEST POINTS FOR EACH ELEMENT
Narrow Beam (Level N)
Wide Beam (Level W)
Horizontal
Vertical
Horizontal
Vertical
-3°
-2°
-7°
-2°
+3°
-2°
+7°
-2°
0°
0°
0°
0°
Table 5.7
November 1998
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Issue B
5.4.4 Luminous Intensity Uniformity
5.4.4.1 The luminous intensity uniformity, shall be separately met for each colour.
5.4.4.2 When measured on axis and at the combined angles, as listed in table 5.7, for a narrow or
wide beam without external illuminance the ratio of the average of the highest 3 elements outputs
to the average of the lowest 3 element outputs shall not exceed 2.5:1.
5.4.4.3 When measured as above the ratio of the outputs of any two elements shall not exceed 5:1.
5.4.5 Colours
5.4.5.1 For signs optical performance level 2:(a)
(b)
Character legends shall only be white, white/yellow or yellow.
Symbol colours shall be as authorised in the current version of The Traffic Signs
Regulations and General Directions.
5.4.5.2 When measured with the test module fully dimmed on axis and at the appropriate horizontal
and vertical viewing angles defined in 5.4.3, colour co-ordinates shall be within the limits given in
Table 5.3 and fig 5a.
November 1998
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Issue B
SECTION 6
TEST MODULES
November 1998
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Issue B
SECTION 6: TEST MODULES
6.1 Introduction
6.1.1 Production signs will normally be too large to allow optical testing in the laboratory. For this
reason it will be necessary for the supplier to produce Test Modules for all laboratory testing and
certification. See Fig 5A for Test Module example.
6.1.2 The Test Modules shall be subject to optical performance testing to demonstrate compliance
with this specification.
6.2 General Requirements
6.2.1 The supplier shall provide Test Modules, which shall be optically functional models of the
production signs, and shall faithfully reproduce their operational characteristics.
6.2.2 If a supplier wishes to use pixel spacing of variable pitch he shall submit a test module with
two matrices one with minimum and one with maximum pixel spacing.
6.2.3 For each certification programme subject to this specification, modules comprising a
minimum of 5x5 elements or 100mm square shall be submitted.
6.3 Test Modules
6.3.1 Test modules shall be manufactured to comply with the following requirements:
(a)
shall be complete in respect of the fitment of all optical components of the production sign,
which includes all backing boards, screens, louvres and cowls where these are employed.
All components of the optical system shall be in their correct physical position and
orientation. Material surfaces shall be finished to the standard that will be achieved within
the production equipment.
(b)
shall be provided with all necessary power supplies, character generation, control device
and dimming circuitry necessary for complete stand-alone operation.
(c)
shall be of a size and weight compatible with ease of laboratory handling.
(d)
shall be provided with fittings allowing ease of mounting to a test goniometer. (Ref: Test
house requirements)
(e)
shall contain a facility suitable for monitoring light source power consumption.
(f)
shall provide the necessary control system to maintain the luminance ratio over the range of
external illumination <4 lux to 40,000 lux. The control system shall also control the test
module for selection of individual elements (uniformity test) and the 'all on'/'all off' modes
November 1998
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TR 2136
Issue B
necessary for the Luminance/Luminance ratio test as in para 8.1.3.
(g)
shall be capable of normal operation when inverted or mounted on their side unless
otherwise advised by the supplier.
(h)
shall include a test point to allow for the measurement of the parameter(s) used for each of
the luminance ratio settings.
6.4 Operation
6.4.1 Supplied light sources must be suitably aged so that their electrical and optical characteristics
are as stable as possible. This is considered satisfactory, whenever two measurements of luminous
intensity being made at an interval of 15 minutes in a given direction, do not differ by more than ±
1.5%.
6.4.2 The supplier shall provide documentary and safety instructions detailing all necessary
installation and operational procedures.
ELEMENT
VARIABLE MESSAGE SIGN
TEST MODULE (SCHEMATIC)
Max. weight = 40 kg
EMITTER
CELL
50mm
MINIMUM
400mm MAXIMUM
60 x 60 mm +-5mm
INPUT FOR PIXEL
SELECTION CONTROL
POWER INPUT
500mm
MAXIMUM
INPUT FOR CONTROL
OF MODULE OUTPUT
400mm MAXIMUM
Figure 6a
November 1998
Traffic Systems & Signing
Drawing Office No. 2401
27
TR 2136
Issue B
SECTION 7
TEST AND CERTIFICATION
November 1998
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Issue B
SECTION 7: TEST AND CERTIFICATION REQUIREMENTS
7.1 General Requirements
7.1.1 For the purposes of this Specification it shall be necessary to carry out testing and
certification of test modules according to the following categories:
(a)
Testing and certification by third party optical test house.
(b)
Technical verification by observation of third party optical test house as specified by the
supplier.
(c)
Certification by the manufacturer (supplier) requiring verification by the third party optical
test house.
(d)
Certification by the manufacturer (supplier).
7.1.2 Test and certification requirements shall be as specified by the supplier.
7.2 Third Party Optical Test House
7.2.1 Any third party optical test house, which is commissioned to carry out tests and certification
to this specification, must be NAMAS accredited to the following applicable European standards:
EN 45001 - General criteria for the operation of testing laboratories.
EN 45002 - General criteria for the assessment of testing laboratories.
EN 45003 - General criteria for laboratory accreditation bodies.
EN45011 - General criteria for certification bodies operating product certification.
7.3 Certification by Supplier
7.3.1 Any supplier who is required to certify equipment or parts of equipment must comply with
the requirements of EN 45014:1989 - General criteria for suppliers' declaration of conformity.
7.3.2 The supplier shall certify that the test module(s) submitted for test and certification shall be
identical in characteristics and performance to all production units to which it, and the requested
certification, relate.
7.4 Test House Certification
7.4.1 A certificate of testing shall be raised for each separate module provided by the supplier.
7.4.2 Where more than one module is provided by the supplier in support of certification for any
one sign, each certificate shall be clearly identified with its dependent module and cross-referenced
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to each other. A certificate shall only be signed and issued when a sign/module has successfully
passed all tests applicable to it.
7.4.3 On completion of the testing / certification, the module(s) shall be returned to the supplier for
isolation in bond according to the Agency's requirements.
7.4.4 In event of a module or modules failing to pass the certification requirements it shall be
returned to the supplier for further action. Should the supplier require a re-test after modifications
it is the responsibility of the test house to ensure that the module fully meets the requirements of the
specification in its entirety before issuing a test certificate.
7.4.5 A certificate of compliance shall only be issued when a test module has fully met the
requirements of this specification in any performance class, regardless of the requirements of the
supplier.
7.5 Test House Report
7.5.1 As part of the approval procedure the Agency shall have unrestricted access to all
information relating to the testing carried out for type approval and shall be able to discuss any or
all aspects of that testing with the appropriate test house.
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DETAILS TO BE FOUND ON A TYPICAL TEST CERTIFICATE
DOCUMENT
Test House:
NAMAS Ref:
Sign/Module Product Ref No: Serial No:
Manufacturer/Supplier:
Requested performance level of Certification:
Viewing Angle:
Luminous Intensity Uniformity
Colour:
Colours luminance level balance :
Stroke Width ( ref Table 2):
Control values for luminance ratio readings:
4 lux :
40 lux :
400 lux :
4,000 lux :
40,000 lux:
Set up for random luminance ratio (between 10,000 and 40,000 lux) value:
Minimum Luminance level (without ext.illuminance)
Performance level Achieved:
Test House Report Reference:
Signature and Grade:
Date:
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SECTION 8
GLOSSARY OF TERMS
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SECTION 8: GLOSSARY OF TERMS
Border: A surround to the sign display providing an improved visibility of the sign by means of
broadening its size and by providing suitable visible contrast with the sign background.
Candela (Cd): S I unit of luminous intensity.
Candela per square meter (Cd.m-²): S I unit of luminance.
Cell: The reactive part of an element, which is used in conjunction with the emitter(s) but not,
including the background. Not every technology used a cell.
Character Height: The distance between centres of adjacent vertical elements multiplied by the
number of vertical elements.
Character Height/Symbol Height : The height of a character or symbol.
Character Matrix: A number of elements constructed in a matrix from which characters may be
formed.
Character Separation : The background horizontal space between two adjacent characters within
a line of text.
Character/Symbol Width : The width of a character or symbol.
Character Width: The distance between centres of adjacent horizontal elements multiplied by the
number of horizontal elements.
Chromaticity: Relating to colour.
Colour Boundaries : Area in chromaticity diagram, bounded by segments of straight lines. The
area is given by the equations of straight lines.
Continuous : (message, legend or legend background): A message is considered continuous
when its legend background and the parts of its legend, being supposed to appear as unbroken
regular surfaces and lines are realised by means of unbroken regular surfaces and lines as the ones
used in the case of static road signs, rotating prisms and internally back illuminated signs. The same
definition applies separately to the legend background or to the legend.
Discontinuous : (Message, legend or legend background): A message is considered as
discontinuous when its legend background and/or the parts of its legend, being supposed to appear
as unbroken regular surfaces and lines, are realised by means of spaced elements (dots, dashes and
similar).The same definition applies separately to the legend background or to the legend.
Element : The basic visual (light emitting or reflective) object in the display surface of a VMS,
activated in conjunction with other elements with the purpose of forming the desired message. It
may coincide with the basic visual device material used to construct the sign or may result from
clustering a few of such devices simultaneously activated or switched-off.
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Equivalent Area (of an element) : A quality involved in the visual observation of an element,
which when viewed from a distance is perceived to have an increased area.
Equivalent Diameter: Visualised diameter of a display element (equivalent to stroke width).
Emitter: The light emitting part of an element . One element may have one or more emitters.
Fluorescent Sign : A sign whose legend(s) and/or legend background is made visible by using
materials, which emit light of different wavelengths from those absorbed.
(a)
fixed (as in the case of non-restricted signs or of those non-restricted signs having fixed
characters and symbols positions);
(b)
free (as in the case of non-restricted signs implemented using an element lattice or matrix
extended to the whole display surface);
(c)
partially free (when the display surface is implemented using separate lattices for symbols
and texts, or for different lines of text or for different words within texts.
Illuminance: The area-density of light falling from an external source onto a surface.
Legend : A configuration of visual elements - symbols, text and other shapes - produced to convey
a given message.
Legend Background : The uniformly coloured surface against which the legend is seen and which
makes it visible by means of colour and/or luminance difference. In some cases it is to be
considered as a meaningful part of the message.
Legibility : The legibility of a sign is a measure of how readily an observer may recognise symbols
or texts. It is normally measured in terms of the threshold distance at which a sign becomes legible.
Light Emitting Sign : A sign using light emitting devices in the display surface, with the purpose
of realising legend(s) and/or legend background.
Line Separation : The background vertical space between characters belonging to two adjacent
lines of a text within a legend.
Luminance: Luminous intensity per unit area leaving, passing through or arriving at a surface in a
given direction. (Cd/m-²)
Luminance Ratio: The ratio of luminance emitted from an active sign face, to that of the sign face
when not active, when illuminated by an external source. The external source shall simulate various
conditions experienced in the field of application.
Luminous Intensity Uniformity: The luminance intensity ratio of two parts of a character or
symbol having the same colour, under defined observation conditions.
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Luminous Intensity: The luminous intensity of a point source (or an element of a source) in any
direction is the ratio of luminous flux emitted by a source in an infinitely small cone containing this
direction, to the solid angle of the cone.
Viewing Angle :The angle of horizontal or vertical rotation at which a luminance ratio
measurement is made.
Lux: S I unit of illuminance.
Matrix : A reference grid whose intersections may hold the centre of the elements used in a sign or
in a legend background or in a legend. A matrix may be extended to the whole display surface or
to part of it. Axes X and Y of the grid may or may not be orthogonal; spacing of intersections on
X and Y axes may be constant or varying; in the first case the matrix will be called regular, in the
second case it will be called irregular.
Optical Performance Class : A category assigned to a sign complying with a specified level of
performance.
Pictogram (symbol): Displayed graphic comprising multiple display elements.
Reflective Sign : A sign whose legend(s) and/or legend background is made visible by reflective
light from daylight or other sources.
Retroreflective Sign : A reflective sign whose legend(s) and/or legend background is activated by
vehicle headlights.
Road Traffic Sign: A legal sign that conveys, to road vehicular and pedestrian traffic, a
prohibition, restriction, requirement, warning or information. A device that provides a visual
message by virtue of its situation, shape, colour or pattern, which can incorporate symbols or
alphanumeric characters. A sign in legal definition also covers audible and tactile devices, but for
the purpose of this document the definition is limited to a visual sign. The term applies to the whole
device i.e. it includes any supporting structure.
Sign : A device that provides a visual message by virtue of its situation, shape, colour or pattern,
which can incorporate symbols or alphanumeric characters. A sign in legal definition also covers
audible and tactile devices, but for the purpose of the present document the definition is limited to a
visual sign.
Sign Application : The application of a sign (for example: urban area, motorway, etc).
Sign Background : The part of environmental scenery, which immediately surrounds the front
face of a sign.
Sign Category : A category of usage assigned to the sign (for example: warning, obligation,
direction etc).
Sign Class : A category assigned to a sign complying with specified physical parameters.
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Sign Face : The visible part of a sign comprising the display surface and the backing-board when it
exists.
Sign Type : A category which identifies the visual technology employed (for example: reflective,
retroreflective, light-emitting etc).
Stroke Width : The width of active elements forming a line of a character or symbol, expressed in
millimetres; for light emitting or reflective elements, this may be related to equivalent area.
Variable Message Sign (VMS) : A sign for the purpose of displaying one of a number of legends
that may be changed or switched off as required.
Visibility : Range of visual perception. It is normally measured in terms of the threshold distance
at which a sign becomes visible. For the purpose of this document it is conventionally related to a
set of objectively measurable parameters.
Visual Performance (of a sign or of a message) : Visibility and legibility of a sign or of a message
under varying visual conditions, taking into consideration human factors.
Width to Height Ratio : The ratio of character width to a given character height.
Words Separation : The separation between the closest characters of adjacent words in a line of
text.
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SECTION 9
REFERENCES
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SECTION 9: REFERENCES
EN 45001 General Criteria for Certification Bodies operating product certification
EN 45002 General Criteria for the Assessment of Testing Laboratories
EN 45003 General Criteria for Laboratory Accreditation Bodies
EN 45011 General Criteria for Certification Bodies operating Product Certification
EN 45014 General Criteria for Suppliers' Declaration of Conformity
CIE Publ.69 Methods of categorising Luminance and Illuminance meters.
CIE Publ. 54/1982 Measurement of Luminous Intensity.
CIE Publ. 70/1987 Measurement of Luminous Intensity.
CIE 1931 Limits for signal colours. Boundary equations in terms of CIE (1931) chromaticity coordinates.
Working Drawings for Traffic Sign Design and Manufacture, published by S.O.( Stationary Office)
in three volumes:
Vol 1, ISBN 0-11-551624-7
Vol 2, ISBN 0-11-551627-1
Vol 3, ISBN 0-11-551719-7
Traffic Signs Manual, Chapter 7, Design of Traffic Signs,
ISBN 0-11-551700-6
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SECTION 10
HISTORY
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SECTION 10: HISTORY
Draft 1 for issue A July 1991.
Draft 2 for issue A January 1993.
Draft 3 for issue A February 1993.
Draft 4 for issue A July 1993.
Draft 5 for issue A August 1993.
Draft 6 for issue A October 1993.
Issue A July 1995.
Draft Issue B for comment May 1998.
Issue B August 1998
Issue B2 October 1998
Issue B November 1998
M.J.SMITH November 1998
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APPENDIX 1
TEST PROCEDURES
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APPENDIX 1: TEST PROCEDURES
A1.Introduction
A1.1 The tests for VMS modules outlined in this appendix are those necessary to meet the optical
performance requirements of Section 5.and shall only be carried out by a NAMAS accredited test
house.
A1.2 Tests shall be carried out using optical test modules as specified in Section 6.
A1.3 Tests may be carried out by appropriate methods except where specific methods, formulae
and test equipment are given. In all cases the requirement to achieve accuracy of specified results is
paramount.
A2.General requirements
A2.1 The Optical tests shall be conducted at an optical test house having been accredited under an
agreed accreditation scheme in accordance with paragraph 7.2.
A2.2 Adequate precautions shall be taken to eliminate the effects of stray light from all other
sources when conducting light and colour measurements.
A2.3 All testing is to be carried out with a laboratory ambient temperature of 20 + 3°C.
A2.4 All optical tests shall be repeated for each individual colour to be used within the sign.
A3.Test Module
A3.1 The test module shall be as described in Section 6.
A3.2 Test modules may be inverted or be operated on their side, subject to the recommendations of
the supplier, should this simplify the physical arrangement of the test equipment. (e.g. for solar
simulator tests). In which case, consideration shall be given to the correct optical orientation of
components and surfaces with that of the test and measurement equipment to ensure a
representative assessment.
A4.Test Area for Luminance measurements
A4.1 All Luminance measurements shall be obtained over a module face test area, which meets the
following criteria:
(a)
Consists at minimum of a 5 x 5 matrix of elements as shown at Figure A1.
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(b)
If a square which just encloses a 5 x 5 matrix of elements should have a side of less than
100mm then the test matrix shall include further elements, of the same type and pitch, to fill
a square of side equal to, or greater than 100mm (see Figure A2).
(c)
Matrix elements may consist of more than one light emitter (see Figure A3).
(d)
Where fixed characters or symbols are formed by the physical arrangement of equally
spaced single light elements, then the test area shall meet the overall matrix size and
dimensions of 4.1(a) and 4.1(b). The separation of elements shall be equal to the pitch of
the single elements forming the character or symbol (see Figure A4).
(e)
Where fixed characters or symbols are formed by the physical arrangement of equally
spaced groups of light elements, then the test area shall meet the overall matrix size and
dimensions of 4.1(a) and 4.1(b). The separation of element groups in the test area shall be
the same as that of the element groups forming the character (see Figure A3 ).
A4.2 Measurements shall be taken over a circular area bounded by the square test area of emitters
as detailed in FiguresA1 to A4 as appropriate.
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TEST AREA 5 x 5 MATRIX
A
Measurement area
A = Five element minimum or 100mm.
Figure A1
Traffic Systems & Signing
Drawing Office No. 2401
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TEST AREA 100mm
A
Measurement area
A = Minimum 100mm.
Figure A2
Traffic Systems & Signing
Drawing Office No. 2401
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TEST AREA 100mm
D1
Measurement area
Emitters = Active segments
Element = Passive segments
Cell = Natural rectangle which
surroundsemitters and element
thus givesbasic unit dimension
for a Matrix
A
B1
B1
B1 = Cell spacing
C1 = Emitter spacing
D1 = Element separation
D
C
B = Cell
C = Emitter
D = Element
C1
B
If the emitters are not symmetrical around
the centre of the cell the horizontal and
vertical equivalent stroke width will be
different
Figure A3
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TEST AREA 100mm
A
B
B
Measurement area
B
A = Minimum 100mm
B = Element spacing
Figure A4
Traffic Systems & Signing
Drawing Office No. 2401
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A5. Initial Procedures
A5.1 All modules shall be suitable for operation in accordance with minimum supply as specified
by the manufacturer.
A5.2 Measurements must not be commenced until the luminous sources have been in operation for
a sufficient period of time, so as to be stabilised. This is considered satisfactory whenever two
measurements of luminous intensity being made at an interval of 15 minutes in a given direction, do
not differ by more than ± 3%.
A6. General Test Equipment
A6.1 All test and measurement equipment shall be capable of fully performing the functions
necessary to carry out optical performance testing to the certification levels required of this
specification.
A6.2 All measurement equipment shall be within its calibration period as stated for that equipment.
A6.3 The spectral sensitivity of the detector shall closely follow the CIE spectral luminous
efficiency curve V(Σ). The illuminance or luminance meter used for the photometric measurements
shall meet the following requirements according to CIE Publ. 69:
V(Σ) match error
f'1 ≤ 3
Linearity error
f3 ≤ 1
Display unit error f4 ≤ 3
Fatigue error
f5 ≤ 0.5
Temperature coefficient ∝ ≤ 0.2%/K
A6.4 The luminous intensity uniformity is measured with the optical unit on a goniometer. The
angles in table 8 are to correspond with a goniometer , where the horizontal axis is fixed and the
vertical axis is moveable in space, (type 1 CIE Publ. No. 70/1987). For a goniometer with another
arrangement the angles have to be recalculated correspondingly ( see CIE Publ. 54/1982 Appendix
B).
A7. Specific Test Equipment
A7.1 External Solar Source
A7.1.1 The solar simulator source shall have spectral content close to that of natural daylight and a
colour temperature of between 5000K and 6000K.
A7.1.2 The solar simulator source, in conjunction with an optical attenuation device, shall be
capable of achieving levels of illuminance between 40,000 and 4 lux, which shall be uniform (±
10%) over the area of measurement.
A8. Optical Tests
A8.1 Luminance ratio measurements
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A8.1.1 The measurement configuration of the sign, solar simulator source and photometer shall be
arranged in accordance with Figure A5.
NB where the solar source is floor mounted it will be necessary to carry out tests with the test
module inverted.
A8.1.2 For the following levels of illumination from the external solar source, the sign's luminance
over the test area shall be measured, 40000, 400, 40 and <4 Lux. An additional measurement shall
be taken with a random illuminance ≤40000 Lux and ≥400 Lux. The measurements shall be taken
with the sign in the following states:
(a)
With all elements of the sign test area active.
(b)
With all elements of the sign test area inactive.
A8.1.3 All illuminance measurements from the solar simulator shall be averaged across the test area
face, and shall be controlled within an accuracy of +10% of the values specified in 8.1.3.
A8.1.4 Luminance ratios shall be calculated for all levels of external illuminance as follows:
LR = ( La - Lb ) / Lb
Where: La is the measured luminance resulting from the active sign under external illumination.
Lb is the measured luminance resulting from the inactive sign under external
illumination.
A8.1.5 The levels of performance required are as in Table 5.1 for optical performance level 1, and
Table 5.6 for optical performance level 2.
NOTE: Several formulae exist for the calculation of contrast ratio. It is therefore important that
only the above formula be used for the assessment of equipment to this specification.
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VMS LUMINANCE RATIO
TEST ARRANGEMENTS
o
o
2 +-
Solar Source
δ
o
<- 3 +-
o
α 10+o
y
A
ε
α
o
<- 3 +-
β
o
o
<0.5+-
Photometer
o
R
NOT
To ensure optimum
users should use reference
to align their sights to the
viewing
Set by supplier
he builds test
β is measured and
by test
Figure A5
November 1998
Reference
o
o
=0x;0
o
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A8.2 Viewing Angle
A8.2.1 The viewing angle performance of the test module(s) is to check the ability of the sign to be
read from any point across a four lane motorway when the sign is cantilever mounted, shall be
certified using a series of luminance ratio tests.
A8.2.2 The test method shall be the same as for the luminance/luminance ratio tests in as given in
paragraph.8.1 but with the photometer moved to the required angles.
A8.2.3 There are two different levels of requirement, which can be associated with either
performance 1 or performance 2 certifications.
A8.2.3.1 Level N (narrow beam) = ± 50 horizontal; -2.50 vertical.
A8.2.3.2 Level W (wide beam) = ± 100 horizontal; -2.50 vertical.
A8.2.4 The requirements for each are as detailed in Tables 5.2 and 5.6.
A8.2.5 Within the field of measurement, the light pattern shall be substantially uniform, i.e. the
light intensity in each direction at each degree point shall meet at least the level achieved by the next
consecutive measurement.
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A8.3 Luminous Intensity Uniformity
A8.3.1 Luminance or luminous intensity uniformity tests are required to ensure all active elements
can be clearly seen from any point across a four-lane motorway when the sign is cantilever
mounted. Mis-alignment of elements could cause loss of legibility when viewed from different
positions.
A8.3.2 The luminance or luminous intensity of individual elements shall be measured on the
geometric axis and at the combined angular positions detailed at Tables 5.3 and 5.7, without
external illuminance from the solar source.
A8.3.3 Measurements shall be carried out from a range, which is far enough distant to ensure due
regard to the inverse square law.
A8.3.4 A minimum of 25 adjacent individual elements shall be measured.
A8.3.5 The following formula shall be applied to the 3 highest and lowest measurements of the sets
of readings:
Mean average of highest three elements
Mean Average of lowest three elements
A8.3.6 For signs optical performance level 1 the result shall be within the limits given in paragraph
5.3.4, and for signs optical performance level 2 within the limits given in paragraph 5.6.4.
A8.3.7 For each of the sets of readings, the output of any three individual elements shall not vary by
more than the limits given in paragraph 5.3.4.2 for optical performance level 1 and paragraph
5.4.4.2 for optical performance level 2.
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A8.4 Colour
A8.4.1 The measurements of colour required by this specification may be made by any method,
which gives results of the required high standard of accuracy.
A8.4.2 Colour measurements shall be in terms of chromaticity co-ordinates (CIE 1931 Standard
colorimetric system) as given in paragraph 5.3.5 for signs optical performance level 1, and
paragraph 5.4.5 for signs optical performance level 2.
A8.4.3 The requirement for strict enforcement of colour boundaries is to allow maximum
differentiation between colours to aid identification by those persons suffering colour deficiency
problems.
A8.4.4 Colour measurements shall be carried out over the maximum inside area of the test circle
being fully influenced by the elements.
A8.4.5 Care should be taken to ensure that only the chromaticity of the emitted coloured light is
measured and that adequate precautions are taken to eliminate stray light from other sources.
A8.4.6 The test module shall be operated according to the conditions specified by the supplier at
fully dimmed output.
A8.4.7 Colour shall be measured along the geometric axis and at the horizontal and vertical angle
positions as per Tables 5.2,5.6.
A8.4.8 To determine the chromaticity of the sign, light may be received directly by the measuring
instrument or reflected via a white diffusing screen, care being taken to ensure that the light is
received in a suitable direction from the sign and that the part of the beam of light which enters the
instrument is representative of the light issuing in other directions which may be effective in service.
A8.4.9 For reflective measurements in a particular direction from the sign, the diffusing screen shall
be placed to receive the light normally at a sufficient distance to ensure that the apparent colour of
the screen is uniform and that it is receiving light substantially equally from all parts of the light
emitting aperture of the equipment.
A8.4.10 For reflective measurements the measuring instrument shall be set to receive light from the
screen at an angle of 45 degrees.
A8.4.11 The reflecting screen may be any recognised standard white reflecting material, e.g.
Barium Sulphate.
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