1970L0157 — EN — 28.04.1981 — 004.001 — 1
This document is meant purely as a documentation tool and the institutions do not assume any liability for its contents
►B COUNCIL DIRECTIVE
of 6 February 1970
on the approximation of the laws of the Member States relating to the permissible soundlevel and
the exhaust system of motor vehicles
(70/157/EEC)
(OJ L 42, 23.2.1970, p. 16)
Amended by:
Official Journal
No page date
►M1Commission Directive 73/350/EEC of7 November 1973 L 321 33 22.11.1973
►M2Council Directive 77/212/EEC of8 March 1977 L 66 33 12.3.1977
►M3Commission Directive 81/334/EEC of13 April 1981 L 131 6 18.5.1981
Amended by:
►A1Act ofAccession ofDenmark, Ireland and the United Kingdom ofGreat
Britain and Northern Ireland L 73 14 27.3.1972
▼B
COUNCIL DIRECTIVE
of 6 February 1970
on the approximation of the laws of the Member States relating to
thepermissiblesoundlevelandtheexhaustsystemofmotorvehicles
(70/157/EEC)
THE COUNCIL OF THE EUROPEAN COMMUNITIES,
Having regard to the Treaty establishing the European Economic
Community, and in particular Article 100 thereof;
Having regard to the proposal from the Commission;Having regard to the Opinion ofthe European Parliament (
1);
Having regard to the Opinion ofthe Economic and Social Committee (2);
Whereas the technical requirements which motor vehicles must satisfy
pursuant to national laws relate, interalia, to the permissible sound level
and the exhaust system;
Whereas those requirements differ from one Member State to another;
whereas it is therefore necessary that all Member States adopt the same
requirements either in addition to or in place oftheir existing rules, in
order, in particular, to allow the EEC type approval procedure whichwas the subject ofthe Council Directive (
3) of6 February 1970 on the
approximation ofthe laws ofthe Member States relating to the typeapproval ofmotor vehicles and their trailers to be applied in respect of
each type ofvehicle;
HAS ADOPTED THIS DIRECTIVE:
Article 1
For the purposes ofthis Directive, ‘vehicle’ means any motor vehicle
intended for use on the road, with or without bodywork, having at least
four wheels and a maximum design speed exceeding 25 kilometres per
hour, with the exception ofvehicles which run on rails, agriculturaltractors and machinery and public works vehicles.
Article 2
No Member State may, on grounds relating to the permissible sound
level and the exhaust system, refuse to grant EEC or national type-approval in respect ofa type ofmotor vehicle or type ofexhaust systemor component ofsuch a system regarded as a separate technical unit,
— ifthe vehicle satisf ies the requirements ofAnnex I as regards the
sound level and exhaust system,
— ifthe exhaust system or any component thereof , considered as a
separate technical unit within the meaning ofArticle 9a ofDirective
70/156/EEC satisfies the requirements of Annex II.
Article 2a
1. No Member State may, on grounds relating to the permissible
sound level and the exhaust system, refuse or prohibit the sale,
registration, entry into service or use ofany vehicle in which the soundlevel and the exhaust system satisfy the requirements of Annex I.
2. No Member State may, on grounds relating to the permissible
sound level and the exhaust system, prohibit the placing on the marketofan exhaust system or any component thereofconsidered as a separatetechnical unit within the meaning ofArticle 9a ofDirective 70/156/EEC1970L0157 — EN — 28.04.1981 — 004.001 — 2
(1) OJ No C 160, 18.12.1969, p. 7.
(2) OJ No C 48, 16.4.1969, p. 16.
(3) OJ No L 42, 23.2.1970, p. 1.▼M3
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if , within the meaning ofArticle 2, it is ofa type in respect ofwhich a
type-approval has been granted.
Article 3
The amendments necessary for adjusting the requirements of the Annex
so as to take account oftechnical progress, with the exception ofthe
requirements set out under ►M3items 5.2.2.1 and 5.2.2.5 ofAnnex
I◄, shall be adopted in accordance with the procedure laid down in
Article 13 ofthe Council Directive on the type approval ofmotorvehicles and their trailers.
Article 4
1. Member States shall put into force the provisions containing the
requirements needed in order to comply with this Directive withineighteen months of its notification and shall forthwith inform the
Commission thereof.
2. Member States shall ensure that the texts ofthe main provisions of
national law which they adopt in the field covered by this Directive arecommunicated to the Commission.
Article 5
This Directive is addressed to the Member States.1970L0157 — EN — 28.04.1981 — 004.001 — 3
▼B
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ANNEX I
EEC TYPE-APPROVAL IN RESPECT OFTHE SOUND LEVEL OFA
TYPE OFMOTOR VEHICLES
1. DEFINITIONS
1.1. Type of vehicle for the purposes of EEC type-approval as
regards its sound level
For the purposes ofthis Directive, ‘type ofvehicle’ means
vehicles which do not differ essentially as regards the following
parts:
1.1.1. the shape or materials ofthe bodywork (particularly the engine
compartment and its soundproofing);
1.1.2. the length and width ofthe vehicle;1.1.3. the type ofengine (two- or f our-stroke, reciprocating or rotary
piston, number and capacity ofcylinders, number and type of
carburettors or injection systems, arrangement ofvalves, rated
maximum power and corresponding engine speed (S));
1.1.4. the transmission system, particularly the number ofgears and
their ratios;
1.1.5. the number, type and arrangement ofthe exhaust systems;
1.1.6. the number, type and arrangement ofthe intake systems.
1.2. Exhaust and intake systems
1.2.1. ‘Exhaust system’ means a complete set ofparts necessary to
reduce the noise produced by the vehicle's engine exhaust.
1.2.2. ‘Intake system’ means a complete set ofparts necessary to
reduce the noise produced by the vehicle's engine intake.
1.2.3. For the purposes ofthis Directive, these systems do not include
the manifolds.
1.3. Different types of exhaust or intake system
‘Different types of exhaust or intake system’ means systems
characterized by fundamental differences, such as the following:
1.3.1. systems bearing different trade marks or trade names;
1.3.2. systems in which the characteristics ofthe materials ofa
component differ, or in which the components are of different
shape or size; a change in the plating procedure (galvanization,
aluminium coating, etc.) is not deemed to produce a difference
oftype;
1.3.3. systems in which the operating principles ofat least one
component differ;
1.3.4. systems in which the components are combined differently.
1.4. Component of an exhaust or intake system
‘Component ofan exhaust or intake system’ means one ofthe
separate components which together form the exhaust system
(e.g. exhaust pipes, the silencer proper) or the intake system
(e.g. air filter).
2. APPLICATION FOR EEC TYPE-APPROVAL
2.1. The application for EEC type-approval in respect of the sound
level ofa type ofmotor vehicle must be submitted by the
manufacturer of the vehicle or his authorized representative.
2.2. It must be accompanied by the undermentioned documents in
triplicate and the following information:
2.2.1. a description ofthe type ofvehicle with ref erence to the points
mentioned in item 1.1 above. The numbers and/or symbols
identifying the engine type and vehicle type must be indicated;1970L0157 — EN — 28.04.1981 — 004.001 — 4
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2.2.2. a list, with appropriate identification, of the component parts of
the exhaust and intake systems;
2.2.3. a drawing ofthe entire exhaust system with an indication ofits
position on the vehicle;
2.2.4. a detailed drawing ofeach component so that it can be easily
located and identified, and an indication of the materials used.
2.3. A vehicle representative ofthe type in respect ofwhich type-
approval is sought must be submitted to the technical service
responsible for the tests by the vehicle manufacturer or his
authorized representative.
2.4. At the request ofthe technical service, a specimen ofthe
exhaust system and an engine ofat least the same cylinder
capacity and rated maximum power as that fitted to the vehicle
in respect ofwhich type-approval is sought must also be
submitted.
3. MARKINGS
3.1. The exhaust and intake system components, excluding fixing
hardware and pipes, must bear:
3.1.1. the trade mark or name ofthe manuf acturer ofthe systems and
their components;
3.1.2. the manufacturer's trade description.3.2. These markings must be clearly legible and indelible.
4. EEC TYPE-APPROVAL
4.1. Ifan application within the meaning ofitem 2.1 is approved, the
competent authority will draw up a certificate, corresponding to
the type which appears in Annex III, to be attached to the EEC
vehicle type-approval certificate.
5. SPECIFICATIONS5.1. General specifications
5.1.1. The vehicle, its engine and exhaust and intake systems must be
designed, constructed and mounted such that, under normal
conditions ofuse and notwithstanding the vibrations to which
they may be subject, the vehicle satisfies the requirements of
this Directive.
5.1.2. The systems must be designed, constructed and mounted so that
reasonable resistance to the corrosion phenomena to which they
are exposed is obtained having regard to the conditions ofuse of
the vehicle.
5.2. Specifications relating to sound levels
5.2.1. Method of measurement
5.2.1.1. The sound emitted by the type ofvehicle submitted f or EEC
type-approval must be measured in accordance with each ofthe
two methods described in item 5.2.2.4 in the case ofmoving
vehicles and item 5.2.3.4 in the case ofstationary vehicles,
respectively (
1).
5.2.1.2. The two values measured as specified in item 5.2.1.1, above,
must be recorded in the test report and in a certificate
corresponding to the model shown in Annex III.
5.2.2. Sound level of moving vehicles
5.2.2.1. Limiting values
The sound level measured in accordance with items 5.2.2.2 to
5.2.2.5, inclusive, ofthis Annex shall not exceed the f ollowing
limits:1970L0157 — EN — 28.04.1981 — 004.001 — 5
(1) A stationary vehicle test is conducted in order to establish a reference value for the
authorities which employ this method for the inspection of vehicles in service.
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Vehicle categoriesValues
expressed in
dB(A) (deci-
bels (A))
5.2.2.1.1. Vehicles intended for the carriage of passen-
gers, and comprising not more than nine seats
including the driver's seat80
5.2.2.1.2. Vehicles intended for the carriage of passen-
gers, comprising more than nine seats including
the driver's seat and having a maximum
permissible mass not exceeding 3·5 tonnes81
5.2.2.1.3. Vehicles intended for the carriage of goods,
and having a maximum permissible mass not
exceeding 3·5 tonnes81
5.2.2.1.4. Vehicles intended for the carriage of passen-
gers, comprising more than nine seats including
the driver's seat and having a maximum
permissible mass exceeding 3·5 tonnes82
5.2.2.1.5. Vehicles intended for the carriage of goods and
having a maximum permissible mass exceeding
3·5 tonnes86
5.2.2.1.6. Vehicles intended for the carriage of passen-
gers, comprising more than nine seats including
the driver's seat and having an engine power
equal to or exceeding 147 kW85
5.2.2.1.7. Vehicles intended for the carriage of goods,
having an engine power equal to or exceeding
147 kW and a maximum permissible mass
exceeding 12 tonnes88
5.2.2.2. Measuring instruments
5.2.2.2.1. Acoustic measurements
The apparatus used for measuring the noise level must be a
precision sound-level meter ofthe type described in Publication
179 ‘Precision sound level meters’, second edition, ofthe
International Electrotechnical Commission (IEC). Measure-
ments must be carried out using the ‘fast’ response of the
sound-level meter and the ‘A’ weighting curve which are also
described in that publication.
At the beginning and end ofeach set ofmeasurements, the
sound-level meter must be calibrated according to the
manufacturer's instructions by means of an appropriate sound
source (e.g. a pistonphone). The test must be considered invalid
ifthe sound-level meter errors registered during this calibration
exceed 1 dB.
5.2.2.2.2. Speed measurements
The engine speed and vehicle speed on the test section shall be
determined with an accuracy of3 % or better.
5.2.2.3. C onditions ofmeasurement
5.2.2.3.1. Test site
The test site must consist ofa central acceleration section
surrounded by a substantially flat test area. The acceleration
section must be level; the track surface must be dry and such
that rolling noise remains low.
The test track must be such that the conditions ofa f ree sound
field between the sound source and the microphone are attained
to within 1 dB. This condition shall be deemed to be met ifthereare no large sound-reflecting objects such as fences, rocks,
bridges or buildings within 50 m ofthe centre ofthe
acceleration section. The surface of the site must be made of
hard materials such as concrete, asphalt or any other
acoustically equivalent material within a minimum radius of
10 m around the centre ofthe acceleration section and be f ree of
powdery snow, tall grass, loose soil or cinders.1970L0157 — EN — 28.04.1981 — 004.001 — 6
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There must be no obstacle which could affect the sound field
within the vicinity ofthe microphone and no persons shall stand
between the microphone and the sound source. The observer
carrying out the measurements must so position himselfas not
to affect the readings of the measuring instrument.
5.2.2.3.2. Meteorological conditions
Measurements must not be made in poor atmospheric condi-
tions. It must be ensured that the results are not affected by gusts
ofwind.
5.2.2.3.3. Ambient noise
For measurements, the A-weighted sound level ofsound sources
other than those of the vehicle to be tested and of wind effects
must be at least 10 dB(A) below the sound level produced by the
vehicle. A suitable windscreen may be fitted to the microphone
provided that account is taken of its effect on the sensitivity and
directional characteristics ofthe microphone.
5.2.2.3.4. Condition ofthe vehicle
For these measurements, the vehicle must be in running order as
defined in item 2.6 of Annex I to Directive 70/156/EEC and,
except in the case ofvehicles which cannot be uncoupled,
without trailer or semi-trailer.
The vehicle's tyres must be ofthe type normally f itted to such
vehicles by the manufacturer and must be inflated to the
appropriate pressure(s) for the unladen vehicle.
Before the measurements are made, the engine must be brought
to its normal operating condition as regards temperatures,
settings, fuel, spark plugs, carburettor(s), etc. (as appropriate). If
the vehicle is fitted with fan(s) having an automatic actuating
mechanism, this system must not be interfered with during the
measurements.
Only the normal highway drive must be engaged in vehicles
with more than two drive wheels.
5.2.2.4. Method ofmeasurement
5.2.2.4.1. Nature and number ofmeasurements
The maximum sound level expressed in A-weighted decibels
(dB(A)) shall be measured as the vehicle is driven between lines
AA′and BB ′(Figure 1). The measurement shall be invalid ifan
abnormal discrepancy between the peak value and the general
sound level is recorded.
At least two measurements must be taken on each side ofthe
vehicle.
5.2.2.4.2. Positioning ofthe microphone
The microphone must be located at a distance of7·5 ± 0·2 m
from the reference line CC ′(Figure 1) ofthe track and 1·2 ± 0·1
m above the ground. Its axis ofmaximum sensitivity must be
horizontal and perpendicular to the path ofthe vehicle (line
CC′).
5.2.2.4.3. Conditions ofoperation
5.2.2.4.3.1. General conditions
For all measurements, the vehicle must be driven in a straight
line over the acceleration section in such a way that the
longitudinal median plane ofthe vehicle is as close as possible
to the line CC ′.
The vehicle must approach the line AA ′at a steady initial road
speed as specified in items 5.2.2.4.3.2 and 5.2.2.4.3.3. When the
front end of the vehicle has reached the line AA ′, the throttle
must be fully opened as quickly as practically possible. This
throttle position must be maintained until the rear end ofthe
vehicle reaches the line BB ′; the throttle must then be returned
to the idling position as quickly as possible.
The trailers ofarticulated vehicles which cannot be uncoupled
must not be taken into account as regards the crossing ofline
BB′.1970L0157 — EN — 28.04.1981 — 004.001 — 7
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5.2.2.4.3.2. Approach speed
The vehicle must approach the line AA ′at a steady speed
corresponding to the lower ofthe two f ollowing speeds:
— the speed corresponding to an engine speed equal to three-
quarters ofthe speed (S) at which the engine develops rated
maximum power;
— 50 km/h.
Ifthe vehicle is f itted with an automatic gearbox which has no
manual selector, it must be tested at different approach speeds:
30, 40 and 50 km/h or at three-quarters ofmaximum road speed
ifthis value is lower. The test result will be that obtained f rom
the speed producing the maximum sound level.
5.2.2.4.3.3. Choice ofgear ratios (in vehicles f itted with gearboxes).
5.2.2.4.3.3.1. Manually-operated, non-automatic gearbox.
5.2.2.4.3.3.1.1. Vehicles in categories M1and N1(1)fitted with a gearbox having
not more than four forward gear ratios must be tested in second
gear.
Vehicles in these categories fitted with a gearbox having more
than four forward gear ratios are to be tested in second and third
gear in turn. Only overall gear ratios intended for normal road
use must be considered. The arithmetic mean ofthe sound levels
recorded for each of these two conditions must be calculated.
5.2.2.4.3.3.1.2. Vehicles other than those in categories M1and N1(2) in which
the total number off orward gear ratios is X (including the ratios
obtained by means ofan auxiliary gearbox or a multiple-ratio
drive axle) must be tested using, in turn, ratios equal to or higher
thanX
2(3). The test result will be that obtained from the ratio
producing the maximum sound level.
Notwithstanding the provisions ofitems 1.1.2 and 1.1.4,
vehicles having the same type ofengine and exhaust and intake
systems, but different lengths or widths and different overall
gear ratios, may be regarded as vehicles ofthe same type. In this
case, it will be sufficient to test a single vehicle representative of
the type in question, in principle, by selecting as the test vehicle
that with the lowest weight in running order.
Ifthe maximum sound level is obtained between the ratiosX
2
and X, the vehicle selected shall be deemed representative ofits
type.
Ifthis is not the case, the tests must be extended to cover the
whole range ofoverall gear ratios to be taken into consideration
for vehicles of this type.
5.2.2.4.3.3.2. Automatic gearbox fitted with manual selector.
If the vehicle is fitted with a manual selector with X forward
positions, the test must be conducted with the selector in
position X; the forced change-down facility (e.g. ‘kick-down’)
must be put out ofaction. Ifautomatic change-down occurs af ter
the line AA ′, has been crossed, the test must be restarted using,
as necessary, the higher ofthe two selector positions X-1 and X-
2, which enables the test to take place without automatic
change-down (the forced change-down facility continuing to be
out ofaction).
Ifthe vehicle is f itted with a manually-operated auxiliary
gearbox or a multiple ratio drive axle, the position corre-
sponding to normal town driving must be used. The special
selector positions for slow manoeuvres, or braking, must not be
used.1970L0157 — EN — 28.04.1981 — 004.001 — 8
(1) In accordance with the definition given in item 0.4 of Annex I to Directive 70/156/EEC
(OJ No L 42, 23. 2. 1970).
(2) In accordance with the definition given in item 0.4 of Annex I to Directive 70/156/EEC
(OJ No L 42, 23. 2. 1970).
(3)I fX
2does not correspond to a whole number, the nearest higher ratio must be used.
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5.2.2.5. Interpretation ofresults
5.2.2.5.1. To take account ofinaccuracies in the measuring instruments,
the result obtained from each measurement shall be determined
by deducting 1 dB(A) from the meter reading.
5.2.2.5.2. The measurements shall be considered valid if the difference
between two consecutive measurements on the same side ofthe
vehicle does not exceed 2 dB(A).
5.2.2.5.3. The highest sound level measured shall constitute the test result.
Should the result exceed the maximum permissible sound level
for the category of vehicle tested by 1 dB(A), two further
measurements shall be made. Three ofthe f our measurements
thus obtained must fall within the prescribed limits.
5.2.3. Sound level of the stationary vehicle
5.2.3.1. Sound level in the vicinity ofvehicles
In order to facilitate subsequent checks on vehicles in use, the
sound level must be measured close to the exhaust system outlet
in accordance with the following requirements and the
measurement results entered in the test report drawn up for
the purpose of issuing the certificate referred to in Annex III.
5.2.3.2. Measuring instruments5.2.3.2.1. Acoustic measurements
A precision sound-level meter as defined in item 5.2.2.2.1 must
be used for the measurements.
5.2.3.2.2. Measurements ofengine speed
The engine speed shall be determined by means ofa tachometer
having an accuracy of3 % or better. The tachometer must be a
separate one from the one of the vehicle.
5.2.3.3. C onditions ofmeasurement
5.2.3.3.1. Test site (Figure 2)
Any area not subject to significant acoustic disturbance may be
used as a test site. Flat surfaces which are covered in concrete,
asphalt or any other hard surfacing and possess a high degree of
reflectivity are particularly suitable; surfaces consisting of earth
which has been tamped down must not be used. The test site
must be in the f orm ofa rectangle, the sides ofwhich are at least
3 m from the sides of the vehicle. This rectangle must not
contain any significant obstacles, e.g. an individual other than
the observer and the driver. The vehicle must be positioned
within the abovementioned rectangle so that the microphone is
at least 1 m from any kerbstone.
5.2.3.3.2. Meterological conditions
Measurements must not be made in poor atmospheric condi-
tions. It must be ensured that the results are not affected by gusts
ofwind.
5.2.3.3.3. Ambient noise
Readings on the measuring instruments produced by ambient
noise and wind must be at least 10 dB(A) below the sound level
to be measured. A suitable windscreen may be fitted to the
microphone provided that account is taken of its effect on the
sensitivity ofthe microphone.
5.2.3.3.4. Condition ofthe vehicle
The vehicle engine must be brought to normal running
temperature before measurements commence. If the vehicle is
fitted with fan(s) having an automatic actuating mechanism, this
system shall not be interfered with during the sound-level
measurements.
During measurements, the gear lever must be in the neutral
position.1970L0157 — EN — 28.04.1981 — 004.001 — 9
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5.2.3.4. Method ofmeasurement
5.2.3.4.1. Nature and number ofmeasurements
The maximum sound level expressed in A-weighted decibels
(dB(A)) must be measured during the operating period referred
to in item 5.2.3.4.3.
At least three measurements must be taken at each measuring
point.
5.2.3.4.2. Position ofthe microphone (Figure 2)
The microphone must be located level with the exhaust outlet or
0·2 m above the test-track surface, whichever is the higher. The
microphone diaphragm must face the exhaust outlet at a distance
of0·5 m f rom the latter. The axis ofmaximum sensitivity ofthe
microphone must be parallel to the track surface at an angle of
45º ± 10º to the vertical plane defined by the direction in which
the exhaust gases are emitted.
The microphone must be positioned to the side ofthis vertical
plane which gives the greatest possible distance between the
microphone and the vehicle contour.
Ifthe exhaust system has several outlets, the centres ofwhich
are not more than 0·3 m apart, and which are connected to the
same silencer, the microphone must face the outlet closest to the
vehicle contour or the outlet which is the highest above the track
surface. In all other cases separate measurements must be taken
at each ofthem, the highest f igure recorded being taken as the
test value.
In the case ofvehicles f itted with a vertical exhaust outlet (e.g.
commercial vehicles), the microphone must be positioned at the
level ofthe exhaust outlet, f acing upwards with its axis vertical.
It must be positioned at a distance of0·5 m f rom the side ofthe
vehicle closest to the exhaust outlet.
Where the design ofthe vehicle is such that the microphone
cannot be located as shown in Figure 2 because ofthe presence
ofobstacles which f orm part ofthe vehicle (e.g. spare wheel,
fuel tank, battery compartment), a drawing clearly indicating the
position for the microphone must be made when the measure-
ment is conducted. As far as possible, the microphone must be
more than 0·5 m from the nearest obstacle, and its axis of
maximum sensitivity must face the exhaust outlet from the
position least concealed by the abovementioned obstacles.
5.2.3.4.3. Conditions ofengine operation
Engine speed must be stabilized at three-quarters ofthe speed
(S) at which the engine develops rated maximum power.
When constant engine speed is reached, the throttle must be
rapidly returned to the idling position. The sound level must be
measured over an operating period comprising briefmainte-
nance ofconstant engine speed and the entire deceleration
period, the maximum sound-level meter reading being taken as
the test result.
5.2.3.5. Results (test report)
5.2.3.5.1. The test report drawn up for the purpose of issuing the
certificate referred to in Annex III shall indicate all relevant
data, particularly those used in measuring the sound ofthe
stationary vehicle.
5.2.3.5.2. Readings, rounded off to the nearest decibel, shall be taken from
the measuring instrument.
Only those values obtained from three consecutive measure-
ments which do not differ by more than 2 dB(A) respectively
will be taken into consideration.
5.2.3.5.3. The highest ofthese three values shall constitute the test result.
5.3. Exhaust systems containing fibrous materials
5.3.1. Fibrous materials shall not be used in the construction of
silencers unless suitable measures are undertaken at the design
or production stages to ensure that the efficiency required to
comply with the limits imposed in item 5.2.2.1 is achieved on1970L0157 — EN — 28.04.1981 — 004.001 — 10
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the road. Such a silencer shall be considered to be efficient on
the road ifthe exhaust gases are not in contact with the f ibrous
materials or ifthe silencer ofthe prototype vehicle tested in
accordance with the requirements ofitems 5.2.2 and 5.2.3 has
been put into a normal state for road use before the sound-level
measurements are taken. This can be achieved by using one of
the three tests described in items 5.3.1.1, 5.3.1.2 and 5.3.1.3,
below, or by removing the fibrous materials from the silencer.
5.3.1.1. Conti nuous road operation for 10 000 km
5.3.1.1.1. About halfthis operation shall consist oftown driving and the
other halfoflong-distance runs at high speed; continuous road
operation can be replaced by a corresponding test-track
programme.
5.3.1.1.2. The two speed regimes must be alternated on several occasions.5.3.1.1.3. The complete test programme must include a minimum of10
breaks ofat least three-hours duration in order to reproduce the
effects of cooling and any condensation which may occur.
5.3.1.2. C onditioning on a test bench
5.3.1.2.1. Using standard parts and observing the vehicle manufacturer's
instructions, the silencer must be fitted to the engine, which is
coupled to a dynamometer.
5.3.1.2.2. The test must be conducted in six six-hour periods with a break
ofat least 12 hours between each period in order to reproduce
the effects of cooling any condensation which may occur.
5.3.1.2.3. During each six-hour period, the engine shall be run under the
following conditions in turn:
1. Five minutes at idling speed;
2. One-hour sequence under ¼ load at ¾ofrated maximum
speed (S);
3. One-hour sequence under ½ load at ¾ofrated maximum
speed (S);
4. 10-minute sequence under full load at ¾ofrated maximum
speed (S);
5. 15-minute sequence under ½ load at rated maximum speed
(S);
6. 30-minute sequence under ¼ load at rated maximum speed
(S).
Total duration ofthe six sequences: three hours.
Each period must comprise two sets ofthe six abovementioned
sequences.
5.3.1.2.4. During the test, the silencer must not be cooled by a forced
draught simulating normal airflow around the vehicle. Never-
theless, at the request ofthe manuf acturer, the silencer may be
cooled in order not to exceed the temperature recorded at its
inlet when the vehicle is running at maximum speed.
5.3.1.3. C onditioning by pulsation
5.3.1.3.1. The exhaust system or components thereofmust be f itted to the
vehicle referred to in item 2.3 or the engine referred to in item
2.4. In the former case the vehicle must be mounted on a roller
dynamometer. In the second case, the engine must be mounted
on a dynamometer.
The test apparatus, a detailed diagram ofwhich is shown in
Figure 3, must be fitted at the outlet of the exhaust system. Any
other apparatus providing equivalent results is acceptable.
5.3.1.3.2. The test apparatus must be adjusted in such a way that the
exhaust-gas flow is alternately interrupted and re-established by
the quick-action valve for 2 500 cycles.
5.3.1.3.3. The valve must open when the exhaust-gas back pressure,
measured at least 100 mm downstream ofthe intake f lange,
reaches a value ofbetween 0·35 and 0·40 bar. It must close
when this pressure does not differ by more than 10 % from its
stabilized value with the valve open.1970L0157 — EN — 28.04.1981 — 004.001 — 11
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5.3.1.3.4. The time-delay switch shall be set for the duration of gas
exhaust resulting from the provisions laid down in item 5.3.1.3.3
above.
5.3.1.3.5. Engine speed must be 75 % ofthe speed (S) at which the engine
develops maximum power.
5.3.1.3.6. The power indicated by the dynamometer must be 50 % ofthe
full-throttle power measured at 75 % of engine speed (S).
5.3.1.3.7. Any drainholes must be closed off during the test.
5.3.1.3.8. The entire test must be completed within 48 hours.
Ifnecessary, one cooling period will be observed af ter each
hour.
5.3.2. Ifthe provisions ofArticle 8 (3) ofDirective 70/156/EEC
concerning EEC type-approval are to be applied, the test method
set out in item 5.3.1.2 above must be employed.1970L0157 — EN — 28.04.1981 — 004.001 — 12
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Figure 1
Microphone positions for the measurement of a moving vehicle1970L0157 — EN — 28.04.1981 — 004.001 — 13
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Figure 2
Test site and microphone positions for the measurement of a stationary vehicle
All distances are given in metres1970L0157 — EN — 28.04.1981 — 004.001 — 14
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Figure 3
Test apparatus for conditioning by pulsation
1. Inlet flange or sleeve for connection to the rear of the test exhaust system2. Hand-operated regulating valve3. Compensating reservoir having a capacity off rom 35 to 40 litres4. Pressure switch with an operating range of0·05 to 2·5 bar
5. Time delay switch
6. Impulse counter7. Quick response valve, such as exhaust brake valve 60 mm in diameter, operated by a pneumatic cylinder with an
output of120 N at 4 bar. The response time, both when opening and closing, must not exceed 0·5 second
8. Exhaust gas evacuation9. Flexible pipe
10. Pressure gauge1970L0157 — EN — 28.04.1981 — 004.001 — 15
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ANNEX II
EEC TYPE-APPROVAL OFEXHAUST SYSTEMS AS SEPARATE
TECHNICAL UNITS (REPLACEMENT EXHAUST SYSTEMS)
0. SCOPE
This Annex applies to the type-approval, as separate technical
units within the meaning ofArticle 9a ofDirective 70/156/EEC,
ofexhaust systems or components thereofto be f itted to one or
more given types ofmotor vehicle in categories M1and N1as
replacement parts.
1. DEFINITIONS
1.1. ‘Replacement exhaust system or component thereof’ means any
part ofthe exhaust system def ined in item 1.2.1 ofAnnex I
intended to replace on a vehicle a part ofthe type granted EEC
type-approval with the vehicle in accordance with Annex I.
2. APPLICATION FOR EEC TYPE-APPROVAL
2.1. Application for EEC type-approval in respect of a replacement
exhaust system or component thereofas a separate technical unit
must be submitted by the vehicle manufacturer of the separate
technical unit in question or by their authorized representatives.
2.2. Application for EEC type-approval in respect of each type of
replacement exhaust system or component thereofmust be
accompanied by the undermentioned documents in triplicate and
the following information:
2.2.1. — a description ofthe type(s) ofvehicle to which the system or
components thereof are to be fitted with reference to the
characteristics mentioned in item 1.1 ofAnnex I. The numbers
and/or symbols designating the engine and vehicle type must be
indicated;
2.2.2. — a description ofthe replacement exhaust system indicating
the relative position ofeach system component, together with
mounting instructions;
2.2.3. — detailed drawings ofeach component, so that they can be
easily located and identified, and reference to the materials
used.
These drawings must indicate the place provided for the
compulsory affixing of the EEC type-approval.
2.3. At the request ofthe technical service concerned, the applicant
must submit:
2.3.1. — two examples ofthe system in respect ofwhich application
for EEC type-approval has been made;
2.3.2. — an exhaust system ofthe type originally f itted to the vehicle
when EEC type-approval was granted;
2.3.3. — a vehicle representative ofthe type to which the system is to
be fitted:
— which, as far as its noise level when moving is concerned,
must be in such a condition that it respects the limits in item
5.2.2.1 ofAnnex I and does not exceed by more than 3
dB(A) the values obtained during the type-approval tests and
— which, as far as its noise level when stationary is concerned,
respects the value obtained during the type-approval;
2.3.4. — a separate engine corresponding to the type ofvehicle
described above.
3. MARKINGS
3.1. The replacement exhaust system or its components, excluding
fixing hardware and pipes must bear:
3.1.1. — the trade mark or trade name ofthe manuf acturer ofthe
replacement system and its components;
3.1.2. — the manufacturer's commercial description;1970L0157 — EN — 28.04.1981 — 004.001 — 16
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3.1.3. — the EEC type-approval number preceded by the distinctive
letter(s) ofthe country granting EEC type-approval (1).
3.2. These marks must be clearly legible and indelible.
4. EEC TYPE-APPROVAL
4.1. Ifan application within the meaning ofitem 2.1 is approved, the
competent authority will draw up a certificate corresponding to
the model shown in Annex IV. The type-approval number must
be preceded by the distinctive letter(s) ofthe country granting
EEC type-approval.
5. SPECIFICATIONS5.1. General specifications
5.1.1. The replacement exhaust system or component thereofmust be
designed, constructed and capable ofbeing mounted so as to
ensure that the vehicle complies with the provisions ofthis
Directive under normal conditions ofuse, notwithstanding any
vibrations to which it may be subject.
5.1.2. The exhaust system or components thereofmust be designed,
constructed and capable ofbeing mounted so that reasonable
resistance to the corrosion phenomena to which it/they is/are
exposed is obtained having regard to the conditions ofuse ofthe
vehicle.
5.2. Specifications relating to sound levels
5.2.1. The acoustic efficiency of the replacement exhaust system or
component thereofmust be checked using the methods
described in items 5.2.2.4 and 5.2.3.4 ofAnnex I.
When the replacement exhaust system or component thereofis
mounted on the vehicle referred to in item 2.3.3 of this Annex,
the sound levels obtained using the two methods (stationary and
moving vehicle) must satisfy one of the following conditions:
5.2.1.1. they must not exceed the values obtained when this type of
vehicle was granted EEC type-approval;
5.2.1.2. they must not exceed the sound level values measured on the
vehicle, referred to in item 2.3.3, when this is fitted with an
exhaust system ofthe same type as that f itted to the vehicle
when EEC type-approval was granted.
5.3. Measurement of vehicle performance
5.3.1. The replacement exhaust system or components thereofmust be
such as to ensure that vehicle performance is comparable with
that achieved with the original equipment exhaust system or
component thereof.
5.3.2. The replacement exhaust system or, depending on the
manufacturer's choice, the components of this system must be
compared with the original equipment exhaust system or
components thereof, which are also in new condition, fitted in
turn to the vehicle referred to in item 2.3.3.
5.3.3. The check must take the form of a measurement of pressure loss
under the conditions specified in item 5.3.4.1 or 5.3.4.2. The
value measured with the replacement exhaust system must not
exceed the value measured with the original equipment system
by more than 25 % under the conditions mentioned below.
5.3.4. Test Method
5.3.4.1. Engine test method
The measurement must be conducted on the engine referred to
in item 2.3.4 coupled to a dynamometer.1970L0157 — EN — 28.04.1981 — 004.001 — 17
(1) B = Belgium, D = Federal Republic ofGermany, DK = Denmark, F = France, GR =
Greece, I = Italy, IRL = Ireland, L = Luxembourg, N L = Netherlands, UK = United
Kingdom.
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With the throttle completely open, the bench shall be so adjusted
as to obtain the engine speed (S) corresponding to the rated
maximum power ofthe engine.
For the measurement ofback pressure, the pressure tap must be
placed at the distance from the exhaust manifold specified in
Figures 1, 2 and 3.
5.3.4.2. Vehicle test method
The measurements must be carried out on the vehicle referred to
in item 2.3.3.
The test must be conducted:
— either on a road, or
— on a roller dynamometer.
With the throttle completely open, the engine must be loaded so
as to obtain the engine speed (S) corresponding to the rated
maximum power.
For the measurement ofback pressure, the pressure tap must be
placed at the distance from the exhaust manifold specified in
Figures 1, 2 and 3.
5.4. Additional provisions in respect of exhaust systems or
components thereof filled with fibrous materials
Fibrous materials must not be used in the manufacture of
replacement exhaust systems or components thereofunless
appropriate measures are taken during the design and production
stages to ensure that a level of efficiency is attained
corresponding to the limits set out in item 5.2.2.1 ofAnnex I.
Such a silencing system is deemed to be effective in traffic if the
exhaust gases are not in contact with the fibrous materials or if,
after the removal of the fibrous materials, the sound levels
comply with the requirements set out in item 5.2.1 above, when
the exhaust system is tested on a vehicle in accordance with the
methods described in items 5.2.2 and 5.2.3 ofAnnex I.
Ifthis condition is not observed, the entire exhaust system must
be subjected to conditioning. This must be done using one ofthe
three methods described in items 5.3.1.1, 5.3.1.2 and 5.3.1.3 of
Annex I.
After conditioning, the sound level must be checked as specified
in item 5.2.1 above.
When the procedure described in item 5.2.1.2 is employed, the
applicant for EEC type-approval may ask for the conditioning of
the original equipment exhaust system or submit one which has
been emptied.
6. CONFORMITY OF PRODUCTION
6.1. Any replacement exhaust system or component thereofbearing
an EEC type-approval number pursuant to this Directive must
conform to the approved type of exhaust system and comply
with the requirements ofitem 5 above.
6.2. In order to check conformity as required by item 6.1 above, an
exhaust system or component thereofbearing the EEC type-
approval number must be taken from the series. Production is
deemed to conform with the requirements of this Directive if the
sound levels measured in accordance with item 5.2 do not
exceed the level measured during the EEC type-approval tests of
this type ofexhaust system or component thereofby more than
1 dB(A).1970L0157 — EN — 28.04.1981 — 004.001 — 18
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Backpressure — measuring points
Figure 1
Figure 2 (1)
Figure 3
1970L0157 — EN — 28.04.1981 — 004.001 — 19
(1) Ifthis is not possible, use Figure 3.
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ANNEX III
MODEL
Maximum size: A4 (210 × 297 mm)
1970L0157 — EN — 28.04.1981 — 004.001 — 20
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1970L0157 — EN — 28.04.1981 — 004.001 — 21
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ANNEX IV
MODEL
Maximum size: A4 (210 mm × 297 mm)
1970L0157 — EN — 28.04.1981 — 004.001 — 22
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1970L0157 — EN — 28.04.1981 — 004.001 — 23