Bsi bs au 040 4a 1966 (2000)

BRITISH STANDARD AUTOMOBILE SERIES

BS AU
40-4a:1 966
Incorp orating

C O NFI RME D
APRI L 1 987

Specification for

Motor vehicle lighting
and signalling
equipment —
Part 4a: Sealed beam headlamps

UD C 62 9 . 1 1 3 . 0 1 8: 65 4. 9 1 2 . 8: 62 9 . 1 1 3 . 0 6: 62 8. 9

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Am endm ent No.

1


BS AU 40-4a:1 966

Co-operating organizations

The Illumination Industry Standards Committee under whose supervision this
British Standard was prepared, consists of representatives from the following

Government departments and scientific and industrial organizations:
Association of Public Lighting Engineers*
British Electrical and Allied Manufacturers’ Association
British Glass Industry Research Association
British Railways Board*
Electric Lamp Industry Council*
Electric Light Fittings Association*
Electricity Council, the Generating Board and the Area Boards in England and Wales*
Gas Council
Glass Manufacturers’ Federation
Illuminating Engineering Society*
Independent Lamp Manufacturers’ Export Group*
Institution of Electrical Engineers*
Institution of Gas Engineers
Institution of Municipal Engineers
London Transport Board*
Medical Research Council
Ministry of Aviation*
Ministry of Defence, Navy Department*
Ministry of Housing and Local Government
Ministry of Labour (H.M. Factory Inspectorate)
Ministry of Public Building & Works*
Ministry of Technology — Building Research Station
Ministry of Transport*
National Physical Laboratory (Ministry of Technology)*
Post Office*
Royal Institute of British Architects
Society of British Gas Industries
Society of Glass Technology*

The Government departments and scientific and industrial organizations
marked with an asterisk in the above list, together with the following, were
directly represented on the committee entrusted with the preparation of
this standard.
British Cycle & Motor Cycle Industries Association Ltd.
Electrical Contractors Association (Incorporated)
Greater London Council
Municipal Passenger Transport Association (Incorporated)
Public Transport Association (Incorporated)
Society of Motor Manufacturers & Traders Ltd.
This British Standard, having
been approved by the
Illumination Industry
Standards Committee and
endorsed by the Chairman of
the Engineering Divisional
Council, was published
under the authority of the
General Council on
27 April 1966
© BSI 02-2000
The following BSI references
relate to the work on this
standard:
Committee references LGE/6,
LGG/6/3
Draft for comment D64/1958
ISBN 0 5 80 345 5 3 X

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Amendments issued since publication

Amd. No.
2188

Date of issue
December
1976

Comments
Indicated by a sideline in the margin


BS AU 40-4a:1 966

Contents

Page
Co- operating organizations

Inside front cover

Foreword

ii

Section 1 . General
1

Scope

1

2

Definitions

1

3

Marking

1

Section 2. Tests
4

Sampling and testing procedure

2

5

Dimensions

2

6

Thermal shock

2

7

Current limits

2

8

Photometric requirements and test

2

9

Visual aim

2

10

Life

2

11

Conditions of compliance

10

Figure 1 — 7 in diameter sealed beam headlamp unit

11

Figure 2 — 5

12

# in diameter sealed beam headlamp unit Type 1
Figure 3 — 5 # in diameter sealed beam headlamp unit Type 2

Table 1 — 7 inch 1 2 volt 60/45 watt right hand drive unit (Dip left)
Table 2 — 5
Table 3 — 5

# inch 1 2 volt 37" watt Type 1
# inch 1 2 volt 37" /50 W Type 2 right hand drive unit (Dip left)

Table 4 — 7 inch 1 2 volt 75/50 watt right hand drive unit (Dip left)

© BSI 02- 2000

13
3
4

5
6

Table 5 — 7 inch 1 2 volt 60/50 watt right hand drive unit (Dip left)

7

Table 6 — 5

8

# inch 1 2 volt 37" /60 watt right hand drive unit (Type 2)
Table 7 — 5 # inch, 1 2 volt, 75 watt (Type 1 )

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3

Appendix A Statistical basis

9

i


BS AU 40-4a:1 966

Foreword

This British Standard has been prepared under the authority of the Illumination

Industry Standards Committee after consultation with the Automobile Industry
Standards Committee, and it is based upon data- sheets SMMT 74: 1 960 and
SMMT 77: 1 962 of the Society of Motor Manufacturers and Traders Ltd.
This standard forms Part 4 of BS AU 40; other parts are:
—

Part 1: Side, rear, parking and stop lamps, and direction indicators;

—

Part 2: Reflex reflectors for vehicles, including cycles;

Part 3: Headlamps with prefocused filament lamps (in course of
preparation);

—

—

Part 5: Rotating beacons (in course of preparation).

It will be seen that compliance with this specification is checked by the testing of
samples from batches of units. The statistical basis for the sampling system is
explained in Appendix A to the standard.
All materials and components used in the construction of these units are required
to comply with relevant British Standards.
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 1 3 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.

ii
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© BSI 02- 2000


BS AU 40-4a:1 966

Section 1 . General

2.6
7-inch two-headlamp system

1 Scope

two similar 7 inch sealed beam units used together

This standard specifies requirements for 1 2 volt

on a vehicle

sealed beam headlamp units for use on vehicles, and

2.7

tests for photometric properties, visual aim, current,

four-headlamp system

life and resistance to thermal shock.
NOTE

In general, the inch dimensions given in this

specification are the standard.
Where dimensions are given in both systems, the first figure is

four units used together on a vehicle and lit to
provide the main beam, two units only being lit to
provide the dipped beam

the standard and the second is an approximate conversion. For

NOTE

Two systems are employed at present. The first uses

accurate conversions reference should be made to BS 350,

four 5

inch units, two being Type 1 and two Type 2 and the

“

Conversion factors and tables”.

#

second system is a mixed one using two 7 inch units and
two 5

#

2 Definitions

2.8

For the purposes of this specification the following

batch

inch (Type 1 ) units.

definitions apply:

all the lamps of one type put forward at one time for

2.1

acceptance

mechanically aimable sealed beam units
a sealed unit having three pads on the face of the

3 Marking

lens, pre- aimed during manufacture to form an

The lamp shall be legibly and durably marked with

aiming plane

the following information:

NOTE

The unit is pre- aimed during manufacture to form an

aiming plane normal to the vehicle axis when the beam is
correctly aimed.

2.2
main (driving or upper) beam
a beam of light intended primarily for distant

a) Nominal voltage.
b) Nominal wattage.
c) Trade mark.
d) Where appropriate, a mark indicating the
rule- of- the- road.

illumination of the road, when no other vehicle is

e) With the number of this British Standard,

approaching

i. e. BS AU 40.

2.3
dipped (meeting or lower) beam
a beam of light intended for illumination of the road
ahead of the vehicle when meeting other road users

2.4
7-inch sealed beam unit
a unit 7 inches in diameter having two filaments,
one providing a main beam and the other a dipped
beam

2.5

# -inch sealed beam unit
a unit 5 # inches in diameter. Type 1 has a single

5

NOTE

The mark BS AU 40 on or in relation to the product is a

claim by the manufacturer that it complies with the
requirements of the standard.
The British Standards Institution is the owner of a registered
certification trade mark. This is shown below, enclosed in the
words “Approved to British Standard”. This mark can be used
only by manufacturers licensed under the certification mark
scheme operated by the BSI. The presence of this mark on or in
relation to a product is an assurance that the goods have been
produced to comply with the requirements of the
British Standard under a system of supervision, control and
testing operated during manufacture and including periodical
inspection at the manufacturer’s works in accordance with the
certification mark scheme of the BSI.
Further particulars of the terms of licence may be obtained
from the Director, British Standards Institution, 2, Park Street,
London, W. 1 .

filament which contributes to the main beam and
Type 2 has two filaments, one of which contributes
to the main beam and the other provides the dipped
beam

© BSI 02- 2000
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1


BS AU 40-4a:1 966

Section 2. Tests

8 Photometric requirements and test

4 Sampling and testing procedure

Following the ageing prescribed in Clause 7
the photometric test voltage (given in the

The units for testing shall be selected so as to ensure

appropriate table) shall then be applied to the

proper representation of the batch, as follows:

terminals of the unit.

a)

The units shall be mounted in such a way that the

Metho d of sam p ling.

i)

A b atch of

A.

1 000

units or less .

photo- cell and centre of the unit. This specifies

A b atch p acked in 1 0 o r less

containers .

Units shall be selected from

detailed above, when measured at 60 ft (1 8. 3 m)
A b atch p acked in m ore than 1 0

containers .

Units shall be selected from at

least one half of the total number of
containers, with a minimum of 1 0.
ii)

A b atch of m ore than

1 000

units.

Lamps shall be selected as far as possible from

b)

the H—V point (see Note 2 below) .
The light intensities from a unit mounted as

each container.
B.

aiming plane is perpendicular to a line through the

from the unit face shall comply with the values
given in the appropriate table.

! ° is permissible for any test point.

NOTE 1

A tolerance of ±

NOTE 2

In locating the test points, the line formed by the

intersection of a vertical plane through the lamp axis with the
test screen is designated as V. The line formed by the intersection
of a horizontal plane through the unit centre and the test screen

one third of the number of containers, with a

is designated as H. The point at the intersection of these two lines

maximum of 1 0.

is designated as H—V. The other points on the screen are
designated by similar symbols to indicate the number of degrees

Tests.

i)

For single filam ent units .

of arc above or below H and the number of degrees of arc to the
left or right of V for an observer facing the screen, for
example, 4D—3L is a point 4 degrees below H and 3 degrees to

1 5 shall be selected from the batch, 1 0 units

the left of V, and 1 U—V is a point 1 degree above H in the median

shall be tested in accordance with

vertical plane.

Clauses, 3 , 5 , 7 and 1 0 . The remaining 5 units
shall be tested in accordance with
Clauses 6 , 8 , and 9 .
ii)

For doub le filam ent units.

25 shall be selected from the batch, 1 0 of these
shall be tested in accordance with Clauses 3 , 5
and 7 . 20 of these, including the 1 0 referred to
above, shall be tested in accordance with
Clause 1 0 , 1 0 being tested on the main beam
filament and 1 0 on the dipped beam filament.
The remaining 5 units shall be tested in
accordance with Clauses 6 , 8 and 9 .

9 Visual aim
When the unit is mounted as in Clause 8 , it shall be
possible for the high intensity zone of the main
beam of 7 inch and 5

# inch Type 1 units to be set by

three experienced observers to within maximum
vertical and horizontal deviations of ± 0. 2
and ± 0. 4 degrees respectively at a distance
of 25 ft (7. 6 m).

1 0 Life
When mounted in the position of normal use the
units shall be tested on an a. c. supply at the life test

5 Dimensions
The units shall comply with the dimensions given
in Figure 1 , Figure 2 or Figure 3 as appropriate.

voltage given in the appropriate table, at a nominal
frequency of 50 c/s.
The momentary fluctuations of the test voltage
during the test shall not exceed ± 1 per cent and

6 Thermal shock
The higher- wattage filament shall be operated for
five minutes in the normal- operating position of the
unit at 1 4 volts. The unit shall then be quickly
immersed, lens first, in water at 1 5 ° C until cool.

there shall be no sensible departure of the average
value throughout the test from the specified value.
Lamps shall be switched off twice daily for periods
of not less than 1 5 minutes, such periods not being
considered as part of the life of the lamp.

After this test there shall be neither evidence of

Lamps which are accidentally broken before the

moisture in the unit nor sign of failure in the glass.

completion of the test shall, when necessary, be

7 Current limits

lamps complete the test. Any such broken lamps

replaced to ensure that the required number of

The units shall be aged at the life- test voltage

shall be neglected in calculating the results.

given in Table 1 to Table 7 as appropriate for at

The test shall be considered to have terminated

least 30 minutes. The current passed shall then be

when the requirements of the tables have been

measured with the specified voltage applied to the

satisfied.

terminals of the unit.

2
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© BSI 02- 2000


BS AU 40-4a:1 966

1 1 Conditions of compliance

A batch shall be considered as complying with this
specification if the requirements contained in a)
to e) inclusive below are satisfied. If the batch fails
to satisfy the requirements of any of these clauses,
it shall be deemed not to comply with the
specification.
a) Not more than 1 unit of the sample tested shall
fail any one of the requirements described in
Clauses 3 and 5 .
b) Not more than two units of the sample tested
shall fail any one of the tests described in
Clauses 8 and 9.
NOTE Clause 9 is applicable only to 7-inch and 5# -inch
Type 1 units.

c) The average of the currents passed by the unit
in the sample tested under Clause 7 shall lie
within the appropriate limits shown in the
appropriate tables.
d) No unit shall fail the test prescribed in
Clause 6 .
e) The average life of the sample selected for the
test shall not fall below the minimum average
value specified in the appropriate tables.
f) The number of units in the sample having lives
shorter than 60 per cent of the specified
minimum average shall not exceed the value
given in the appropriate table.

Table 1 — 7 inch 1 2 volt 60/45 watt right hand drive unit (Dip left)

1 A. Photometric requirements at 1 2.8 V on the unit terminals
Main beam
Position

2U—3R & 3L
1U—3R & 3L
" D—V

Dipped beam

Cd Max.

Cd Min.

" D—3R & 3L
" D—6R & 6L
" D—9R & 9L
" D—12R & 12L
2D—V
2D—9R & 9L
3D—V
3D—12R—12L
4D—V
5 000

Position

Cd Max.

1 250

5 000
36 000

1 " U—1L to L
1U—1R to R
" U—1L to 3L

12 000
5 000
3 000

" U—1R to R
800
" D—1L to L 10 000
" D—2L
" D—1R to R 2 000
1D—1R to 6R
1 " D—2L
1 " D—9L
1 " D—9R
12 500
4D—4L
125
10U—90Ua

1 500
5 000
2 000
2 500
1 000

a From the normally exposed surface of the lens

1 000
500
2 000

Cd Min.

3 750
750
10 000
1 500
750

1 B. Current limits at 1 2.8 V on the unit terminals
Average current limits for 1 0 units

Minimum

Main filament:
Dipped filament:

Maximum

4.41 amp
3.31 amp

4.97 amp
3.73 amp

1 C. Life test at 1 4.0 V on the unit terminals
Maximum number of

Minimum
average life of

10 units

Main filament:
Dipped filament:
© BSI 02-2000
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138 h
221 h

units failing

Design life

200 h
320 h

before 60 per cent of

2
2

design life

3


BS AU 40-4a:1 966

Table 2 — 5

# inch 1 2 volt 37" watt Type 1

2A. Photometric requirements at 1 2.8 V on the unit terminals
Main beam
Position

3U—3L & 3R
2U—3L & 3R
1U—3L & 3R

Cd Max.

" D—V
" D—3L & 3R
" D—6L & 6R
" D—9L & 9R

Cd Min.

Position

450

750
3 000

" D—12L & 12R
2D—V
2D—9L & 9R

25 000
12 000
6 000
2 000

3D—V
3D—12D & 12R
4D—V

Cd Max.

2 500

Cd Min.

750
3 000
1 250
1 500
600

2B. Current limits at 1 2.8 V on the unit terminals
Average current limits for 1 0 units

Minimum

2.75 amp

Maximum

3.11 amp

2C. Life test at 1 4.0 V on the unit terminals (Main Beam)
Maximum number of units failing

Minimum average
life of

138 h

4

10 units

Design life

200 h

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before 60 per cent of design life

2

© BSI 02-2000


BS AU 40-4a:1 966

Table 3 — 5

# inch 1 2 volt 37" /50 W Type 2 right hand
drive unit (Dip left)

3A. Photometric requirements at 1 2.8 V on the unit terminals
Main beam
Position

Dipped beam

Cd Max.

3U—3L & 3R
2U—3L & 3R
1U—3L & 3R

" D—V
" D—3L & 3R
" D—6L & 6R
" D—9L & 9R
" D—12L & 12R
2D—V
2D—9L & 9R

3D—V
3D—12L & 12R
4D—V

Cd Min.

Position

300
750
2 000

1U—1R to R
" U—1R to R
" D—1R to R

7 000
3 000
2 000

1 " U—1L to L 1 000
" U—1L to 3L 2 000

1 000
750
2 000

" D—2L
1D—6R
1 " D—2L

1 " D—9L
1 " D—9R
4D—4L
10U to 90Ua

750
1 000
400

2 500

Cd Max.

650
850
2 000

10 000

12 500
125

Cd Min.

3 750
750
12 000
1 500
750

a From the normally exposed surface of the lens
3B. Current limits at 1 2.8 V on the unit terminals
Average current limits for 1 0 units

Minimum

Main filament
Dipped filament

2.75 amp
3.68 amp

Maximum

3.11 amp
4.14 amp

3C. Life test at 1 4.0 V on the unit terminals
Minimum
Design

failing before 60 per cent

of

life

of design life

10 units

Main filament 138 h
Dipped filament 221 h

© BSI 02-2000
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Maximum number of units

average life

200 h 2
320 h 2

5


BS AU 40-4a:1 966

Table 4 — 7 inch 1 2 volt 75/50 watt right hand drive unit (Dip left)
4A. Photometric requirements at 1 2.8 V on the unit terminals
Main beam
Position

2U—3R & 3L
1U—3R & 3L
" D—V

Cd Max.

" D—3R
" D—3L
" D—6L & 6R
" D—9R & 9L
" D—12R & 12L
2D—V
2D—9R & 9L
3D—V
3D—12R & 12L
4D—V
6 000

Dipped beam
Cd Min.

Position

Cd Max.

1 750
7 000
40 000

1 " U—1L to L
1U—1R to R
" U—1L to 3L

1 000
500
2 000

20 000
16 000
6 500

" U—1R to R
" D—1L to L

800
10 000

4 000
2 000
6 000

" D—2L
" D—1R to R
1D—1R to 6R
1 " D—2L
1 " D—9L
1 " D—9R
4D—4L
10U—90Ua

3 000
3 000
1 250

a From the normally exposed surface of the lens

2 000

12 500
125

Cd Min.

4 200
800
11 000
1 700
800

4B. Current limits at 1 2.8 V on the unit terminals
Average current limits for 1 0 units

Minimum

Main filament
Dipped filament

Maximum

5.51 amp
3.68 amp

6.22 amp
4.14 amp

4C. Life test at 1 4.0 V on the unit terminals

Minimum

Main filament
Dipped filament

6

Maximum number

average

Design

of units failing

life of

life

before 60 per cent of

10 units

105 h
221 h

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150 h
320 h

2
2

design life

© BSI 02-2000


BS AU 40-4a:1 966

Table 5 — 7 inch 1 2 volt 60/50 watt right hand drive unit (Dip left)
5A. Photometric requirements at 1 2.8 V on the unit terminals
Main beam
Position

Dipped beam

Cd Max.

2U—V
1U—3L & 3R
H—V

Cd Min.

1 000
2 000
20 000
10 000

3 250
1 500
750

H—3L & 3R
H—6L & 6R
H—9L & 9R
H—12L & 12R
1 " D—V
1 " D—9L & 9R
2 " D—V
2 " D—12L & 12R
4D—V

5 000
1 500
2 500
750

5 000

Position

Cd Max.

10U to 90Ua
1U—1 " R to R
" U—1 " R to R
" D—1 " R to R
1 " U—1L to L

125
700
1 000
2 500
1 400

" U—1L to 3L
" D—1 " L
1D—6R
1 " D—2L

2 700
20 000

1 " D—9R & 9L
2D—15R & 15L
4D—4L
12 500

Cd Min.

8 000
750
15 000
750
700

a From the normally exposed surface of the lens
5B. Current limits at 1 2.8 V on the unit terminals

Average current limits for 1 0 units

Minimum

Main filament
Dipped filament

4.41 amp
3.68 amp

Maximum

4.97 amp
4.14 amp

5C. Life test at 1 4.0 V on the unit terminals
Minimum

Main filament
Dipped filament

© BSI 02-2000
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Maximum number of units

average life

Design

failing before 60 per cent of

of

life

design life

10 units

138 h
221 h

200 h 2
320 h 2

7


BS AU 40-4a:1 966

Table 6 — 5

# inch 1 2 volt 37 " /60 watt right hand
drive unit (Type 2)

6A. Photometric requirements at 1 2.8 V on the unit terminals
Main beam
Position

3U—3L & 3R
2U—3L & 3R
1U—3L & 3R

Cd Max.

Dipped beam
Cd Min.

Position

Cd Max.

300
750
2 000

1U—1R to R
" U—1R to R
" D—1R to R

650
850
2 000

" D—V
" D—3L & 3R
" D—6L & 6R
" D—9L & 9R
" D—12L & 12R

2D—V
2D—9L & 9R

7 000
3 000
2 000

1 " U—1L to L
" U—1L to 3L

1 000
2 000

1 000
750
2 000

3D—V
3D—12L & 12R
4D—V

1 000
400

" D—2L
1D—6R
1 " D—2L
1 " D—9L
1 " D—9R
4D—4L

10U to 90Ua

750

2 500

15 000

Cd Min.

6 000
750
15 000
1 500
750

12 500
125

a From the normally exposed surface of the lens
6B. Current limits at 1 2.8 V on the unit terminals
Average current limits for 1 0 units

Minimum

Main filament
Dipped filament

Maximum

2.75 amp
4.41 amp

3.11 amp
4.97 amp

6C. Life test at 1 4.0 V on the unit terminals
Minimum
Design

failing before 60 per cent of

of

life

design life

10 units

Main filament
138 h
Dipped filament 221 h

8

Maximum number of units

average life

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200 h 2
320 h 2

© BSI 02-2000


BS AU 40-4a:1 966

Table 7 — 5

# inch, 1 2 volt, 75 watt (Type 1 )

7A. Photometric requirements at 1 2.8 V on the unit terminals
Main beam
Position

Cd Max.

Cd Min.

2U—3R
2U—3L
1U—3R

Position

" D—9L
" D—12R

" D—12L

1 250
1 250
7 500

1U—3L
D—V
D—3R

"
"
" D—3L
" D—6R
" D—6L
" D—9R

Cd Max.

Cd Min.

2 000
750
750

7 500
65 000
28 000

2D—V

2D—12R
2D—12L

7 500
500
500

28 000
7 000
7 000

3D—V
3D—12R
3D—12L

2 500
200
200

2 000

4D—V

6 500

* From the normally exposed surface of the lens

7B. Current limits at 1 2.8 V on the unit terminals
Average current limits for 1 0 units

Minimum

Main filament

5.50 amp

Maximum

6.20 amp

7C. Life test at 1 4.0 V on the unit terminals
Minimum
Design

failing before 60 per cent of

of

life

design life

10 units

Main filament

© BSI 02-2000
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Maximum number of units

average life

35 h

50 h

2

9


BS AU 40-4a:1 966

Appendix A Statistical basis

2) 98 per cent of the lamps satisfy each single

It is impracticable and uneconomic to test every

3) 90 per cent of the lamps satisfy each single

lamp in a batch but, by the use of statistical

requirement (Clauses 8 and 9 ) .

requirement (Clauses 3 and 5 ) .

sampling theory, it is possible to design tests on
small samples which will determine whether the

quality of a batch is acceptable.
Accordingly, test quantities, quality limits and
compliance numbers have been so specified that if
the whole of a batch had been tested and found to
comply with each of the following quality
statements, there would be a 0. 975 (39/40)
probability that such a batch, if tested (by sampling)
in accordance with the specification, would be found
to comply with the standard. The quality
statements are:
1 ) 99 per cent of the lamps satisfy each single
requirement (Clause 6 ).

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4) The average values satisfy the requirements
for initial current (Clause 7 ).
A batch of lamps complies with this standard if,
when a sample is tested according to the standard,
in all the test quantities, the numbers of lamps
outside the specified quality limits (such lamps are
not necessarily failures or faulty lamps) are not
greater than the related compliance numbers, and
the average life is not less than the related
minimum average life. Individual lamps are deemed
to comply with the requirements of the standard if
they belong to, and comply consequently upon
belonging to, a batch which complies with the
standard.

© BSI 02- 2000


© BSI 02 - 2 000

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Figure 1 — 7 in diameter sealed beam headlamp unit

BS AU 40-4a:1 966


12
© BSI 02 - 2 000
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Figure 2 — 5

#

in diameter sealed beam headlamp unit Type 1

BS AU 40-4a:1 966


© BSI 02 - 2 000

13

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Figure 3 — 5

#

in diameter sealed beam headlamp unit Type 2

BS AU 40-4a:1 966


BS AU
40-4a:1 966

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