Bsi bs au 152 1970 (2011)

00071693 PDF BRITISH STANDARD AUTOMOBILE SERIES CONFIRMED SEPTEMBER 1990 BS AU 152 1970 Specification for Rear marking plates for vehicles Confirmed February 2011 BS AU 152 1970 This British Standard,[.]

Specification for

Rear marking plates

for vehicles

Confirmed February 2011

BS AU 152:1970

This British Standard, having

been approved by the

Automobile Industry

Standards Committee,

was published under

the authority of the

Executive Board of

the Institution on

30 April 1970

© BSI 02-2000

The following BSI references

relate to the work on this

standard:

Committee reference AUE/1

Draft for comment 69/10282

ISBN 0 580 06160 4

Foreword

This British Standard has been prepared under the authority of the Automobile Industry Standards Committee of BSI at the request of the Ministry of Transport

Its purpose is to provide a specification for rear marking plates for vehicles to

be used in accordance with the appropriate Regulation in order to give following vehicles adequate warning, both by day and by night, of particular types or lengths of vehicles which might constitute a hazard

A British Standard does not purport to include all the necessary provisions of

a contract Users of British Standards are responsible for their correct application

Compliance with a British Standard does not of itself confer immunity from legal obligations.

Summary of pages

This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 12, an inside back cover and a back cover

This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover

Amendments issued since publication

Appendix A Terms and symbols relating to reflex-reflecting devices 6 Appendix B Apparatus and method for accelerated weathering test 7

Figure 3 — Apparatus for accelerated weathering test: assembled views 10 Figure 4 — Apparatus for accelerated weathering test: details of

Figure 5 — Arrangements for measurement of reflective intensity

Table 2 — Fluorescent material: colour limits before and after weathering 2 Table 3 — Minimum CIL per square metre of reflex-reflecting surfaces in

ii blank

1 Scope

This British Standard specifies requirements for

marking plates faced with reflex-reflecting and

fluorescent materials for fitting to the rear of certain

vehicles and trailers

The standard includes requirements for colorimetric

and photometric properties and tests for certain

physical requirements

2 Definitions

For the purposes of this British Standard the

following definitions, together with those given in

Appendix A, apply:

2.1

rear marking plate

a rectangular backing plate faced with

reflex-reflecting and fluorescent materials and,

where appropriate, letters, as prescribed in this

specification

NOTE 1 The direct attachment with adhesive of

reflex-reflecting and fluorescent materials only to the vehicle

does not constitute a rear marking plate for the purposes of this

British Standard.

2.2

sample unit

a complete rear marking plate, as used

NOTE 2 Photometric units such as lumen (lm), candela (cd),

etc., are as defined in BS 233, “Glossary of terms used in

illumination and photometry”.

3 Design

3.1 Dimensions Five types of rear marking plates

are specified, as shown in Figure 2

NOTE Except for the mounting position on the vehicle, Types 2

and 3 are identical.

The dimensions of the plates and of the

reflex-reflecting and fluorescent areas and the

proportions of the letters shall be as prescribed or

otherwise authorized in the appropriate Regulation

3.2 Stiffening When rear marking plates are to be

freely suspended from a vehicle they shall be

stiffened either by flanges integral with the plate

and forming part of it, or by means of a separate

stiffening structure Such separate stiffening need

not be included in the sample unit for the purpose of

the bending and corrosion test in Clause 14.

Rear marking plates that have been stiffened shall

comply with the requirements of Clause 22.

4 Type test

Representative sample units shall be submitted to

an independent testing authority for type testing

The number of sample units to be selected for testing shall be agreed between the manufacturer and the testing authority but will normally comprise not less than two representative samples

of Types 1, 2 or 3, two of Type 4 and two of Type 5 All the sample units submitted shall comply with all the requirements in this standard

5 Marking

Each rear marking plate shall be permanently and legibly marked, in such a position as to be clearly visible when the marking plate is fitted to the vehicle, with the following information:

1) The name, trade mark or other means of identification of the maker

2) The number of this British Standard, i.e BS AU 152

NOTE Attention is drawn to certification facilities offered by BSI; see the inside back cover of this standard.

6 Materials

Rear marking plates may be manufactured from any suitable material which shall perform satisfactorily in service and satisfy the requirements of this standard

7 Preparation and finish of plates

Before the application of the reflex-reflecting and the fluorescent surfaces, the surface of the backing plate shall be free from grease, oil, dirt and any loose

or temporary coatings and shall be suitable for and adequate to receive the materials to be applied

8 Reflex-reflecting and fluorescent surfaces

8.1 Any material may be used for the

reflex-reflecting and the fluorescent areas or borders provided that it is applied so as to give the appearance of a continuous surface and that it complies with all the relevant requirements of this standard

8.2 Where holes are pierced for fixing the rear

marking plate to the vehicle or for attaching letters

to the marking plate, such holes shall be adequately-protected against any deleterious effect

on the applied surface material

Where, after the marking plate has left the maker’s works, it may be pierced with holes which can have

a subsequent deleterious effect on the reflex-reflecting or fluorescent material, the marking plate maker shall attach to each plate a label giving adequate instructions for suitably fixing the plate to the vehicle in order to prevent such deleterious effect

BS AU 152:1970

9 Letters and borders

Letters and borders shall be securely attached to the

rear marking plate so that they cannot be readily

detached therefrom

10 Adhesive marking plates

Where a rear marking plate is intended to be

attached to the vehicle with adhesive, the marking

plate maker shall give adequate instructions for the

preparation of the surface to which it is to be

attached and shall state the materials or surfaces

for which the attachment of his marking plate is

unsuitable

11 Colour

11.1 The colour of the reflex-reflecting material, the

fluorescent material and the letters shall be as

indicated in Figure 2, as appropriate

11.2 Reflex-reflecting material

11.2.1 When the yellow reflex-reflecting surface is

illuminated by CIE Standard Illuminant A1), with

an observation angle of%° and an entrance angle

V = ± 5°, H = 0°, the chromaticity values shall be

within the area on the chromaticity diagram defined

in Table 1

The colour shall have chromaticity co-ordinates

which lie within the area formed by the straight

lines defined by the pairs of points 1 and 2; 2

and 3; 3 and 4; and the spectrum locus

11.2.2 When the yellow reflex-reflecting surface is

illuminated by CIE Standard Illuminant C2) under

the condition of normal incidence ± 10° and viewed

at 45°, the luminance factor shall be 29 % min

and 39 % max

11.3 Fluorescent material The fluorescent

material, when illuminated by CIE Standard Illuminant C2) under the condition of normal incidence ± 10° and viewed at 45°, shall have a dominant wavelength, purity and luminance factor

in accordance with the values given in Table 2

NOTE The luminance factor includes both the reflected and the fluorescent luminous flux.

11.4 Letters The letters on the Types 4 and 5 rear

marking plates shall be black in colour and when illuminated normally by CIE Standard Illuminant

C2) and viewed at 45° they shall have a maximum luminance factor of 5 %

12 Photometric requirements

The coefficient of luminous intensity (CIL) of the reflex-reflecting surfaces of the marking plate, when illuminated by CIE Standard Illuminant A3), shall

be measured for each of the observation angles µ and the entrance angles ¶ specified in Table 3 The CIL at any of the test points in Table 3 at the 2° observation angle shall not exceed 150 cd/lx

For making the necessary measurements, either of the methods recommended by the CIE or the Road Research Laboratory4) for the photometry of reflex-reflecting surfaces shall be used The normal

axis to the plate shall be taken as the H-V direction.

The plate shall not be rotated and all measurements shall be made for & = 0°

The angular subtense values ¾ and ¸ shall not exceed 0° 5½

NOTE An explanation of the terms and symbols used is given

in Appendix A.

Table 1 — Reflex-reflecting material: chromaticity limits

Table 2 — Fluorescent material: colour limits before and after weathering

1) As defined in the proceedings of the 1951 meeting of the International Commission on Illumination (CIE).

2) As defined in the proceedings of the 1931 meeting of the International Commission on Illumination (CIE).

3) As defined in the proceedings of the 1951 meeting of the International Commission on Illumination (CIE).

4) See Road Research Technical Paper No 42, “Reflex reflectors”.

Colour Co-ordinate

Chromaticity co-ordinates of points at the corners

of the area on the chromaticity diagram

Yellow x y 0.5380.460 0.5200.460 0.5600.420 0.5790.420

Exposure Dominant wavelength Excitation purity Luminance factor

Min Max Min Min Max.

Unexposed

300 hours’ exposure

nm

610 600

nm

617

—

%

95 92

%

31

—

%

— 60

Table 3 — Minimum CIL per square metre of reflex-reflecting

surfaces in candelas per lux

13 Accelerated weathering

13.1 Procedure For each test two identical

specimens of a sample unit (see Clause 2) are taken

One specimen shall be stored in the dark in a dry

container for subsequent use as the “reference

unexposed specimen”

The second specimen shall be exposed

for 1 200 hours to an atmospheric weathering test

using the apparatus and the method described in

Appendix B

After the test the specimen shall be washed in a

dilute neutral detergent solution and examined for

compliance with the requirements specified in 13.2

to 13.5 inclusive.

13.2 Visual appearance No area of the exposed

specimen shall show any evidence of cracking,

scaling, pitting, blistering, de-lamination,

distortion, blooming, staining, corrosion or chalking

There shall be no shrinkage in excess of 0.5 % in any

linear direction and no evidence of any adhesion

failure such as edge lifting from the substrate

13.3 Colour fastness

13.3.1 Reflex-reflecting material The colour of the

exposed specimen when compared with that of the

“reference unexposed specimen” (see 13.1) shall

have a fastness rating of not less than 3 when

measured by the Geometric Grey Scale in BS 26625)

13.3.2 Fluorescent material After exposure

for 300 hours to an atmospheric weathering test,

using the apparatus and method described in

Appendix B and washing as in 13.1, the specimen

shall be examined for compliance with 13.2 In

addition, when illuminated by CIE Standard

Illuminant C6) under the condition of normal

incidence ± 10° and viewed at 45°, any shift in

dominant wavelength and change in purity and

luminance factor shall be such that the values are

within the limits given in Table 2

13.4 Effect on CIL value of reflex-reflecting material

13.4.1 For this test, measurements shall be made

only at an entrance angle of 5° and an observation

angle of 0° 12½ by the method given in Clause 11 13.4.2 The CIL of the exposed specimen when dry

shall be not less than 80 % of the relevant value in Table 3

13.4.3 The specimen shall then be subjected to a fine

water spray using the apparatus shown in Figure 5 and kept continuously wetted The CIL of the specimen under this condition shall be not less than 90 % of the value obtained when measured dry

in 13.4.2.

13.5 Effect of dirt on reflex-reflecting material 13.5.1 The tests shall be made using the same

exposed specimen and after the tests described

in 13.4.

13.5.2 The dry specimen shall first be artificially

dirtied by the application of a layer of graphite grease thick enough to obscure the face of the specimen The layer of grease shall then be removed

by washing with a clean mixture of water and a neutral detergent A soft bristle brush may be used

to assist in the removal of the dirt, if necessary

13.5.3 The specimen shall then be tested in accordance with Clauses 11 and 12 and shall

comply with the following requirements:

1) The luminance factor shall be not less than 80 % of the minimum value specified

in 11.2.1.

2) The CIL value at an entrance angle of 5° and

an observation angle of 0° 12½ shall be not less than 80 % of the relevant minimum value specified in Table 3

Colour Observation angle

µ

Entrance angle ¶ Vertical: H H H

Horizontal: 5° left and

5° right

30° left and 30° right

45° left and 45° right

2°

cd/lx

18 2

cd/lx

7 0.75

cd/lx

2.5 0.4

5) BS 2662, “Grey scale for assessing change in colour” (contained in BS 2661-86 & BS 3661, “Methods for the determination of the

colour fastness of textiles”).

6) As defined in the proceedings of the 1931 meeting of the International Commission on Illumination (CIE).

BS AU 152:1970

14 Bending and corrosion (See 3.2)

14.1 Bending In the case of marking plates

constructed solely, excluding the letters, from

all-metal back-plates laminated with

reflex-reflecting and fluorescent materials, a sample

unit with, where appropriate, representative letters

attached shall be bent around a 50 mm diameter

mandrel to an included angle of 90° and then

flattened

Failure or detachment of the letters, where fitted,

shall not constitute failure of the sample unit

14.2 Corrosion resistance The bent and flattened

portion of the sample unit shall then be subjected to

the action of a saline mist for 50 hours, comprising

two periods of exposure of 24 hours each, separated

by an interval of 2 hours during which the specimen

is allowed to dry

The saline mist shall be produced by atomizing, at a

temperature of 35 ± 2 °C, a saline solution obtained

by dissolving 20 ± 2 parts by weight of sodium

chloride in 80 parts of distilled water containing not

more than 0.02 % of impurities

14.2.1 Immediately after completion of the test the

sample shall not show signs of corrosion liable to

impair the efficiency of the device

14.2.2 The CIL of the reflex-reflecting surfaces,

when tested as specified in Clause 12, shall be not

less than those given in Table 3

15 Fuel resistance

15.1 A section of a sample unit not less

than 300 mm long shall, except for the cut edge, be

immersed in a mixture of petrol and benzene

(proportion 90 : 10) for 5 minutes and then

removed

15.2 After a further 5 minutes the section shall be

examined Other than local surface crazing, it shall

not show any visible change

16 Bonding strength

16.1 Where reflex-reflecting or fluorescent surfaces

are laminated or coated to background materials the

adhesion shall be determined in accordance with

Appendix H in BS 873:19597)

16.2 When tested by this method the load required

to produce failure shall be not less than 440 N

17 Water resistance

17.1 A section of a specimen not less than 300 mm

long shall, except for the cut edge, be immersed in water for a period of 20 hours, after which it shall be removed and allowed to dry for 4 hours This test shall be repeated four times

17.2 After completion of this test cycle the section

shall be examined No part shall show evidence of deterioration which would reduce the effectiveness

of the marking plate

18 Thermal resistance

18.1 A section of a sample unit not less

than 300 mm long shall be kept for 12 consecutive hours in a dry atmosphere at a temperature

of 65 ± 2 °C, after which it shall be kept for 20 hours

at a temperature of minus 40 ± 2 °C

18.2 After this test, no cracking or appreciable

distortion of the surfaces, particularly of the optical units, shall be evident

18.3 The optical performance shall then be checked

and shall comply with the requirements of

Clauses 11 and 12.

19 Abrasion resistance

19.1 The outer surfaces of the reflective background

or covering material shall be rubbed by hand for 1 minute using medium pressure with a linen pad and dry quartz powder of nominal sieve aperture size 53 Èm8) and then washed and dried

19.2 The CIL value of the area so treated shall then

be determined and shall not fall below 80 % of the relevant value in Table 3

19.3 There shall be no visual evidence of damage to

the surface coating which would impair the protective function of that coating

20 Attachment of marking plates to the vehicle with adhesive

Marking plates designed to be attached to the vehicle with adhesive shall comply with the

requirements of Clause 16.

For the test, the marking plate shall be applied by the inspecting authority to a surface representative

of that to which the marking plate may be applied

on a vehicle (see Clause 10).

The test shall be carried out at a temperature

of 25 ± 5 °C after the marking plate has been attached to the surface for a period of

between 48 hours and 72 hours

7) BS 873, “The construction of road traffic signs and internally illuminated bollards”.

8) See BS 410, “Test sieves”.

21 Attachment of individual letters

and borders by adhesive

21.1 Where individual letters and borders are to be

attached to the marking plate by adhesive, sample

letters and portions of the borders attached to the

marking plate using the adhesive supplied by the

marking plate manufacturer shall be subjected to

the test specified in Clause 16.

21.2 When tested by this method the load required

to produce failure shall be not less than 440 N

multiplied by the ratio of the area of the samples

tested to that specified in Appendix H in

BS 873:19599)

22 Rigidity of suspended marking plates

22.1 The marking plate shall be placed on two

supports in such a way that the supports are parallel to the shorter edges of the plate, and the distance from either support to the adjacent edge of

the plate shall not exceed L/10 where L is the greater

overall dimension of the plate The plate shall be loaded by means of bags of shot or bags of dry sand

to a uniformly distributed pressure

of 1.5 kN/m2(15 mbar) The deflection of the plate shall be measured at a point mid-way between the supports

22.2 When tested as described in 22.1 the maximum

deflection of the plate under the test load shall not exceed one-fortieth of the distance between the

supports in 22.1 and the residual deflection after

removal of the load shall not exceed one-fifth of the measured deflection under load

9) BS 873, “The construction of road traffic signs and internally illuminated bollards”.

BS AU 152:1970

Appendix A Terms and symbols relating to reflex-reflecting devices

A.1 Terms

1) Reflex reflection Reflection in which light is reflected in directions close to the direction from which it

came This property is maintained over wide variations of the entrance angle

2) Reflex-reflecting optical unit A combination of optical components producing reflex reflection 3) Reflex-reflecting device An assembly ready for use and comprising one or more reflex-reflecting optical

units

4) Effective reflex surface That part of the surface of a reflex-reflecting device which is occupied by an

assembly of reflex-reflecting optical units and which appears continuous at the normal observation distances

5) Reference axis The axis, as defined by the manufacturer of the reflex-reflecting device, which serves

as reference direction for the entrance angles in photometric measurements and in practical use The reference axis usually corresponds to the axis of symmetry, if any, of the effective reflex surface

6) Reference centre The orthogonal projection of the centre of gravity of the effective reflex surface on the

plane nearest to the observer which is tangential to that surface and perpendicular to the reference axis

of the reflex-reflecting device

7) Observation angle The angle between the straight lines connecting the reference centre to the centre

of the receiver and to the centre of the source of illumination

8) Entrance angle The angle between the reference axis and the straight line connecting the reference

centre to the centre of the source of illumination

9) Rotation angle The angle through which the reflex-reflecting device is rotated about its reference axis

starting from one given position

10) Angular subtense of the reflex-reflecting device The angle subtended by the greatest dimension of the

visible area of the effective reflex surface from a specified reference point

11) Illumination at the reflex-reflecting device The illumination measured at the reference centre in a

plane perpendicular to the incident rays and passing through the reference centre

12) Coefficient of luminous intensity (CIL) The value obtained by dividing the luminous intensity

reflected in the direction considered by the illumination of the reflex-reflecting device, for given observation, entrance and rotation angles

13) Colour The colour of the light reflected by the reflex-reflector, defined in terms of its chromaticity

co-ordinates, using the trichromatic system recommended by the International Commission on

Illumination (CIE) in 1931 In this system the colour is expressed in the chromaticity co-ordinates x, y and z, the sum of which is unity The co-ordinate x is an indication of the proportion of red, y of the proportion of green and z of the proportion of blue.

14) Chromaticity The colour quality of the light defined in terms of its chromaticity co-ordinates 15) Uncoloured light White light reflected from the outer surface of a reflex-reflector.

16) Colour temperature The absolute temperature on the Kelvin scale (degrees K) of a full radiator, the

colour of which is as nearly as possible identical with the colour of the white light source

A.2 Symbols (see Figure 1)

A = Area of the effective reflex surface of the reflex-reflecting device

C = Reference centre

NC = Reference axis

Rr = Receiver, observer or measuring device

Cr = Centre of receiver

Ìr = Diameter of receiver Rr, if circular

Se = Source of illumination

Cs = Centre of source of illumination

Ìs = Diameter of source of illumination