1970L0157 — EN — 16.11.1992 — 010.001 — 1
This document is meant purely as a documentation tool and the institutions do not assume any liability for its contents
►B COUNCILDIRECTIVE
of6February1970
ontheapproximationofthelawsoftheMemberStatesrelatingtothepermissiblesoundleveland
theexhaustsystemofmotorvehicles
(70/157/EEC)
(OJ L 42, 23.2.1970, p. 16)
Amended by:
Official Journal
No page date
►M1Commission Directive 73/350/EEC of 7 November 1973 L 321 33 22.11.1973
►M2Council Directive 77/212/EEC of 8 March1977 L 66 33 12.3.1977
►M3Commission Directive 81/334/EEC of 13 April 1981 L 131 6 18.5.1981
►M4Commission Directive 84/372/EEC of 3 July 1984 L 196 47 26.7.1984
►M5Council directive 84/424/EEC of 3 September 1984 L 238 31 6.9.1984
►M6Council Directive 87/354/EEC of 25 June 1987 L 192 43 11.7.1987
►M7Commission Directive 89/491/EEC of 17 July 1989 L 238 43 15.8.1989
►M8Council Directive 92/97/EEC of 10 November 1992 L 371 1 19.12.1992
Amended by:
►A1Act of Accession of Denmark, Ireland and the United Kingdom of Great
Britain and Northern IrelandL 73 14 27.3.1972
►A2Act of Accession of Spain and Portugal L 302 23 15.11.1985
▼B
COUNCILDIRECTIVE
of6February1970
on the approximationof the lawsofthe Member States relating to
the permissible sound level and the exhaust system of motor vehi-
cles
(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 of the European Parliament(
1);
Having regard to the Opinion of the Economic and Social
Committee(2);
Whereas the technical requirements which motor vehicles must satisfy
pursuant to national laws relate, inter alia, 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 samerequirements either in addition to or in place of their existing rules, inorder, in particular, to allow the EEC type approval procedure which
was the subject of the Council Directive(
3) of 6 February 1970 on the
approximation of the laws of the Member States relating to the typeapproval of motor vehicles and their trailers to be applied in respectof eachtype of veh icle;
HAS ADOPTED THIS DIRECTIVE:
Article 1
For the purposes of this 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 perhour, with the exception of vehicles 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 of a type of motor vehicle or type of exhaustsystem or component of sucha system regarded as a separate tech nicalunit,
— if the vehicle satisfies the requirements of Annex I as regards the
sound level and exhaust system,
— if the exhaust system or any component thereof, considered as a
separate technical unit within the meaning of Article 9a of Direc-tive 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, registra-tion, entry into service or use of any vehicle in which the sound leveland the exhaust system satisfy the requirements of Annex I.1970L0157 — EN — 16.11.1992 — 010.001 — 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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2. No Member State may, on grounds relating to the permissible
sound level and the exhaust system, prohibit the placing on the marketof an exhaust system or any component thereof considered as a sepa-
rate technical unit within the meaning of Article 9a of Directive 70/
156/EEC if, within the meaning of Article 2, it is of a type in respectof which a type-approval has been granted.
Article 3
The amendments necessary for adjusting the requirements of the Annex
so as to take account of technical progress, with the exception of therequirements set out under ►
M3items 5.2.2.1 and 5.2.2.5 of Annex
I◄, shall be adopted in accordance with the procedure laid down in
Article 13 of the Council Directive on the type approval of motor vehi-cles 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 theCommission thereof.
2. Member States shall ensure that the texts of the main provisions
of national law which they adopt in the field covered by this Directive
are communicated to the Commission.
Article 5
This Directive is addressed to the Member States.1970L0157 — EN — 16.11.1992 — 010.001 — 3
▼B
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ANNEX I
EEC TYPE-APPROVAL IN RESPECT OF THE SOUNDLEVEL OF A
TYPEOFMOTORVEHICLE
1. DEFINITIONS
For the purposes of this Directive:
1.1. Typeofvehicle
means vehicles which do not differ essentially as regards the
following parts:
1.1.1. the shape or materials of the bodywork (particularly the engine
compartment and its soundproofing);
1.1.2. the length and width of the vehicle;
1.1.3. the type of engine (positive or compression ignition, two- or
four-stroke, reciprocating or rotary piston, number and capacity
of cylinders, number and type of carburettors or injection
systems, arrangement of valves, rated maximum power and
corresponding engine speed(s));
1.1.4. the transmission system, the gear ratio in which the test is
performed and the relevant overall ratio(s);
1.1.5. the number, type and arrangement of the exhaust systems;
1.1.6. the number, type and arrangement of the intake systems.1.1.7. Notwithstanding the provisions of items 1.1.2 and 1.1.4, vehi-
cles other than those in categories M
1and N1(1) having the
same type of engine and/or different overall gear ratios, may
be regarded as vehicles of the same type.
However, if the above differences provide for a different test
method, these differences are to be considered as a change of
type.
1.2. Exhaustandintakesystems
1.2.1. Exhaust systems
means a complete set of parts necessary to reduce the noise
produced by the vehicle's engine exhaust.
1.2.2. Intake systems
means a complete set of parts necessary to reduce the noise
produced by the vehicle's engine intake.
1.2.3. For the purposes of this Directive, these systems do not include
the manifolds.
1.3. Differenttypesofexhaustorintakesystem
means systems characterized by fundamental differences, such
as the following:
1.3.1. systems in which the components bea different trade marks or
trade names;
1.3.2. systems in which the characteristics of the materials of a
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
of type;
1.3.3. systems in which the operating principles of at least one
component differ;
1.3.4. systems in which the components are combined differently.1970L0157 — EN — 16.11.1992 — 010.001 — 4
(1) In accordance withth e definition given in item 0.4 of Annex I to Directive 70/156/EEC
(OJ No L 42, 23. 2. 1970, p. 16).
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1.4. Componentofanexhaustoranintakesystem
means one of the separate components which together form the
exhaust system (e.g. exhaust pipes, the silencer proper) or the
intake system (e.g. air filter).
1.5. Overall gearratio
means the number of turns made by the engine per each turn of
the driving wheels.
2. APPLICATION FOR EEC TYPE-APPROVAL
2.1. The application for EEC type-approval in respect of the sound
level of a type of motor 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 of the type of vehicle with reference to the points
mentioned in item 1.1. The numbers and/or symbols identi-
fying the engine type and vehicle type must be indicated;
2.2.2. a list, withappropriate identification, of th e component parts of
the exhaust and intake systems;
2.2.3. a drawing of the entire exhaust system with an indication of its
position on the vehicle;
2.2.4. a detailed drawing of eachcomponent so th at it can be easily
located and identified, and an indication of the materials used.
2.3. A vehicle representative of the type in respect of which type-
approval is sought must be submitted to the technical service
responsible for the tests by the vehicle manufacturer or his
authorized representative.
2.3.1. In the case of item 1.1.7 the single vehicle, representative of
the type in question, will be selected by the technical service
conducting approval tests, in accordance with the vehicle
manufacturer, as that with the lowest mass in running order
with the shortest length and following the specification laid
down in item 5.2.2.4.3.3.1.2.
2.4. At the request of the technical service, a specimen of the
exhaust system and an engine of at least the same cylinder
capacity and rated maximum power as that fitted to the vehicle
in respect of which type-approval is sought must also be
submitted.
2.5. Before granting type-approval the competent authority must
verify the existence of satisfactory arrangements for ensuring
effective control of the conformity of production.
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 of the manufacturer of the systems and
their components;
3.1.2. the manufacturer's trade description.
3.2. These markings must be clearly legible and indelible, even
when the system is fitted to the vehicle.
4. EEC TYPE-APPROVAL
4.1. If an application within the meaning of 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 type-approval certificate for the vehicle.
5. SPECIFICATIONS
5.1. General specifications
5.1.1. The vehicle, its engine and exhaust and intake systems must be
designed, constructed and mounted suchth at, under normal1970L0157 — EN — 16.11.1992 — 010.001 — 5
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conditions of use 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 of
use of the vehicle.
5.2. Specificationsrelatingtosoundlevels
5.2.1. Method of measurement
5.2.1.1. The sound emitted by the type of vehicle submitted for EEC
type-approval must be measured in accordance witheachof
the two methods described in item 5.2.2.4 in the case of
moving vehicles and item 5.2.3.4 in the case of stationary vehi-
cles, respectively(1).
Vehicles having a maximum permissible mass exceeding 2 800
kg must be subjected to an additional measurement of the
compressed air noise with the vehicle stationary in accordance
withitem 5.4, if corresponding brake equipment is part of th e
vehicle.
5.2.1.2. The values measured as specified in item 5.2.1.1 must be
recorded in the test report and in a certificate corresponding
to the model shown in Annex III. Details of the ambient condi-
tions, namely, test track (type of surface), air temperature, wind
(direction and speed) and ambient noise must also be recorded
in the test report.
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, of this Annex shall not exceed the following
limits:
Vehicle categoriesValues
expressed in
dB (A)
(decibels
(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 seat 74
5.2.2.1.2. Vehicles intended for the carriage of passen-
gers and equipped withmore th an nine seats,
including the driver's seat; and having a
maximum permissible mass of more than 3,5
tonnes and:
5.2.2.1.2.1. — withan engine power of less th an 150 kW 78
5.2.2.1.2.2. — withan engine power of not less th an 150
kW 80
5.2.2.1.3. Vehicles intended for the carriage of passen-
gers and equipped withmore th an nine seats
including the driver's seat; vehicles intended
for the carriage of goods:
5.2.2.1.3.1. — witha maximum permissible mass not
exceeding 2 tonnes 76
5.2.2.1.3.2. — witha maximum permissible mass
exceeding 2 tonnes but not exceeding 3,5
tonnes 77
5.2.2.1.4. Vehicles intended for the carriage of goods and
having a maximum permissible mass
exceeding 3,5 tonnes:
5.2.2.1.4.1. — withan engine power of less th an 75 kW 771970L0157 — EN — 16.11.1992 — 010.001 — 6
(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.
▼M8
Vehicle categoriesValues
expressed in
dB (A)
(decibels
(A))
5.2.2.1.4.2. — withan engine power of not less th an 75
kW but less than 150 kW 78
5.2.2.1.4.3. — withan engine power of not less th an 150
kW 80
However:
— for vehicles of categories 5.2.2.1.1 and 5.2.2.1.3, the limit
values are increased by 1 dB (A) if they are equipped
witha direct injection diesel engine,
— for vehicles with a maximum permissible mass of over two
tonnes designed for off-road use, the limit values are
increased by 1 dB (A) if their engine power is less than
150 kW and 2 dB (A) if their engine power is 150 kW or
more,
— for vehicles in category 5.2.2.1.1., equipped with a manu-
ally operated gear box having more than four forward
gears and withan engine developing a maximum power
exceeding 140 kW/t and whose permissible maximum
power/maximum mass ratio exceeds 75 kW/t, the limit
values are increased by 1 dB (A) if the speed at which the
rear of the vehicle passes the line BB ′(Figure 1) in third
gear is greater than 61 km/h.
5.2.2.2. Measuring instruments5.2.2.2.1. Acoustic measurements
The apparatus used for measuring the noise level must be a
precision sound-level meter of the type described in Publica-
tion 179 ‘Precision sound level meters’, second edition, of the
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 of each set of measurements, the
sound-level meter must be calibrated according to the manufac-
turer's instructions by means of an appropriate sound source
(e.g. a pistonphone). The test must be considered invalid if
the 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 withan accuracy of 3 % or better.
5.2.2.3. C onditions of measurement
5.2.2.3.1. Test site
The test site must consist of a central acceleration section
surrounded by a substantially flat test area. The test accelera-
tion section must be level; the track surface must be dry and
suchth at rolling noise remains low.
The test track must be such that the conditions of a free sound
field between the sound source and the microphone are attained
to within 1 dB. These conditions shall be deemed to be met if
there are no large sound-reflecting objects such as fences,
rocks, bridges or buildings within 50 m of the centre of the
acceleration section. The test-track surface must comply with
the specifications in Annex VI.
There must be no obstacle which could affect the sound field
within the vicinity of the microphone and no persons shall
stand between the microphone and the sound source. The
observer carrying out the measurements must so position
himself as not to affect the readings of the measuring instru-
ment.
5.2.2.3.2. Meteorological conditions1970L0157 — EN — 16.11.1992 — 010.001 — 7
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Measurements must not be made in poor atmospheric condi-
tions. It must be ensured that the results are not affected by
gusts of wind.
5.2.2.3.3. Ambient noise
For measurements, the A-weighted sound level of sound
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 of the micro-
phone.
5.2.2.3.4. Condition of 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 of vehicles which cannot be uncoupled,
without trailer or semi-trailer.
The vehicle's tyres must be of the type normally fitted to such
vehicles by the manufacturer and must be inflated to the appro-
priate 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 of measurement
5.2.2.4.1. Nature and number of measurements
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 if an abnormal discrepancy between the peak value
and the general sound level is recorded.
At least two measurements must be taken on eachside of th e
vehicle.
5.2.2.4.2. Positioning of the microphone
The microphone must be located at a distance of 7,5 ± 0,2 m
from the reference line CC ′(Figure 1) of the track and 1,2 ±
0,1 m above the ground. Its axis of maximum sensitivity must
be horizontal and perpendicular to the path of the vehicle (line
CC′).
5.2.2.4.3. Conditions of operation
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 median
longitudinal plane of the 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 accel-
erator control is fully operated as rapidly as practicable and
held in the fully opened position until the rear of the vehicle
reaches the line BB ′; the accelerator control must be released
as quickly as possible.
The trailers of articulated vehicles which cannot be uncoupled
must not be taken into account as regards the crossing of line
BB′.
5.2.2.4.3.2. Approachspeed
The vehicle must approach the line AA ′at a steady speed
corresponding to the lower of the following two speeds:
— 50 km/h,1970L0157 — EN — 16.11.1992 — 010.001 — 8
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— the speed corresponding to an engine speed equal to three-
quarters of the speed, S, at which the engine develops its
rated maximum power, in the case of vehicles of category
M1and in the case of vehicles of the other categories
having an engine power not greater than 225 kW,
— the speed corresponding to an engine speed equal to half
the speed, S, at which the engine develops its rated
maximum power, in the case of vehicles not belonging to
category M1having an engine power greater than 225 kW.
However, if in the case of vehicles equipped with an automatic
transmission having more than two discrete ratios there is a
change-down to first gear during the test, the manufacturer
may select either of the following test procedures:
— the speed, V, of the vehicle is increased to a maximum of
60 km/hin order to avoid sucha ch ange-down,
or
— the speed, V, must remain at 50 km/h and the fuel supply
to the engine limited to 95 % of the supply necessary for
full load. This condition is considered to be satisfied:
— in the case of a spark-ignition engine, when the angle of
the throttle opening is 90 %,
and
— in the case of a compression-ignition engine, when the
movement of the central rack of the injection pump is
limited to 90 % of its travel.
If the vehicle is equipped with an automatic transmission
which has no manual override, it must be tested at different
approach speeds, namely 30, 40, and 50 km/h, or at three-quar-
ters of maximum road speed if this value is lower. The test
result is that obtained at the speed which produces the
maximum sound level.
5.2.2.4.3.3. Choice of gear ratios (in vehicles fitted with gearboxes)5.2.2.4.3.3.1. Manually-operated, non-automatic gearbox5.2.2.4.3.3.1.1. Vehicles in categories M
1and N1equipped witha manually
operated gearbox having not more than four forward gear ratios
must be tested in second gear.
Vehicles in these categories equipped with a manually operated
gearbox having more than four forward gear ratios must be
tested in second and third gears successively. Only overall
gear ratios intended for normal road use are considered. The
arithmetic mean of the sound levels recorded for each of these
two conditions shall be calculated.
If during the test in second gear, the engine speed exceeds the
engine speed, S, at which the engine develops its rated
maximum power, the test must be repeated with an approach
speed and/or approachengine speed reduced by steps of 5 %
of S until the engine speed attained no longer exceeds S.
However, the vehicles in category M1having more than four
forward gears and equipped withan engine developing a
maximum power greater than 140 kW, and whose permissible
maximum-power/maximum-mass ratio exceeds 75 kW/t, may
be tested in third gear only, provided that the speed at which
the rear of the vehicle passes the line BB ′in third gear is
greater than 61 km/h.
5.2.2.4.3.3.1.2. Vehicles other than those in categories M1and N1in which the
total number of forward gear ratios is x (including the ratios
obtained by means of an auxiliary gearbox or a multiple-ratio
drive axle) must be tested using, in turn, ratios equal to or
higher than x/n(1)(2).
The test result will be that obtained from the ratio producing
the maximum sound level.
Shifting up gears from x/n must be terminated in the gear X
where the engine speed, S, at which the engine develops its1970L0157 — EN — 16.11.1992 — 010.001 — 9
(1) Where: n = 2 for vehicles having an engine power not greater than 225 kW;
n = 3 for vehicles having an engine power greater than 225 kW.
(2) If x/n does not correspond to a whole number, the nearest higher ratio must be used.
▼M8
rated maximum power is for the last time reached when
passing the line BB ′.
In the case of vehicles having different overall gear ratios
(including a different number of gears) the representativity of
the type by the test vehicle is determined as follows:
— if the highest sound level is obtained between the ratios x/n
and X the vehicle selected is deemed representative of its
type,
— if the highest sound level is obtained at ratio x/n the vehicle
selected is deemed representative of its type only for those
vehicles which have a lower overall gear ratio at x/n,
— if the highest sound level is obtained at ratio X the vehicle
selected is deemed representative of its type only for those
vehicles which have a higher overall gear ratio at X.
5.2.2.4.3.3.2. Automatic transmission equipped withmanual override
The test is conducted with the selector in a position recom-
mended by the manufacturer for ‘normal’ driving. External
downshifts (e.g. kickdown) shall be put out of operation.
5.2.2.5. Interpretation of results5.2.2.5.1. To take account of inaccuracies in the measuring instruments,
the result obtained from each measurement is determined by
deducting 1 dB (A) from the meter reading.
5.2.2.5.2. The measurements are considered valid if the difference
between two consecutive measurements on the same side of
the 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 at the corresponding
microphone position. Three of the four measurements thus
obtained at that microphone position must fall within the
prescribed limits.
5.2.3. Sound level of the stationary vehicle
5.2.3.1. Sound level in the vicinity of vehicles
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 instruments
5.2.3.2.1. 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. Measurement of engine speed
The engine speed is determined by means of a tachometer
having an accuracy of 3 % or better. The tachometer may not
be the one fitted to the vehicle.
5.2.3.3. C onditions of measurement
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 form of a rectangle, the sides of
which 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. Meteorological conditions1970L0157 — EN — 16.11.1992 — 010.001 — 10
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Measurements must not be made in poor atmospheric condi-
tions. It must be ensured that the results are not affected by
gusts of wind.
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 of the microphone.
5.2.3.3.4. Condition of the 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 must not be interfered with during the sound-level
measurements.
During measurements, the gear lever must be in the neutral
position.
5.2.3.4. Method of measurement5.2.3.4.1. Nature and number of measurements
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 of the 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 of 0,5 m from the latter. The axis of maximum sensi-
tivity of the microphone must be parallel to the track surface at
an angle of 45º ± 10º to the vertical plane defined by the direc-
tion in which the exhaust gases are emitted.
The microphone must be positioned to the side of this vertical
plane which gives the greatest possible distance between the
microphone and the vehicle contour.
If the exhaust system has several outlets, the centres of which
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 of them, the highest figure recorded
being taken as the test value.
In the case of vehicles fitted with a vertical exhaust outlet (e.g.
commercial vehicles), the microphone must be positioned at
the level of the exhaust outlet, facing upwards with its axis
vertical. It must be positioned at a distance of 0,5 m from the
side of the vehicle closest to the exhaust outlet.
Where the design of the vehicle is such that the microphone
cannot be located as shown in Figure 2 because of the presence
of obstacles which form part of the vehicle (e.g. spare wheel,
fuel tank, battery compartment), a drawing clearly indicating
the position for the microphone must be made when the
measurement 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 of engine operation
Engine speed must be stabilized at three-quarters of the 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 brief mainte-
nance of constant engine speed and the entire deceleration
period, the maximum sound-level meter reading being taken
as the test result.1970L0157 — EN — 16.11.1992 — 010.001 — 11
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5.2.3.5. Results (test report)
5.2.3.5.1. The test report drawn up for the purpose of issuing the certifi-
cate referred to in Annex III must indicate all relevant data,
particularly those used in measuring the sound of the 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
are taken into consideration.
5.2.3.5.3. The highest of these three values shall constitute the test
results.
5.3. Exhaustsystemscontainingfibrousmaterials
5.3.1. Fibrous materials may not be used in the construction of silen-
cers 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 on
the road. Such a silencer is considered to be efficient on the
road if the exhaust gases are not in contact with the fibrous
materials or if the silencer of the prototype vehicle tested in
accordance with the requirements of items 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 half this operation shall consist of town driving and the
other half of long-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 occa-
sions.
5.3.1.1.3. The complete test programme must include a minimum of 10
breaks of at 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 iscoupled to a dynamometer.
5.3.1.2.2. The test must be conducted in six six-hour periods with a break
of at least 12 hours between each period in order to reproduce
the effect of cooling and 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 ¾of rated maximum
speed (S);
3. one-hour sequence under ½ load at ¾of rated maximum
speed (S);
4. 10-minute sequence under full load at ¾of rated 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 of the six sequences: three hours.Eachperiod must comprise two sets of th e 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 of the manufacturer, the silencer may1970L0157 — EN — 16.11.1992 — 010.001 — 12
▼M8
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 thereof must be fitted to the
vehicle referred to in 2.3 or the engine referred to in 2.4. In the
former case the vehicle must be mounted on a roller dynam-
ometer. In the second case, the engine must be mounted on a
dynamometer.
The test apparatus, a detailed diagram of which 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 2500 cycles.
5.3.1.3.3. The valve must open when the exhaust-gas back pressure,
measured at least 100 mm downstream of the intake flange,
reaches a value of between 0,35 and 0,40 bar. It must close
when this pressure does not differ by more than 10 % from
its stabilized value withth e valve open.
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 % of the speed (S) at which the
engine develops maximum power.
5.3.1.3.6. The power indicated by the dynamometer must be 50 % of the
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. If neces-
sary, one cooling period may be observed after eachh our.
5.3.2. If the provisions of Article 8 (3) of Directive 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.
5.4. Compressedairnoise
5.4.1. Method of measurement
The measurement is performed at microphone positions 2 and
6 according to Figure 4, with the vehicle stationary. The
highest A-weighted noise levels are registered during venting
the pressure regulator and during ventilating after the use of
bothth e service and parking brakes.
The noise during venting the pressure regulator is measured
withth e engine at idling speed.
The ventilating noise is registered while operating the service
and parking brakes; before eachmeasurement, th e air-
compressor unit has to be brought up to the highest permissible
operating pressure, and then the engine switched off.
5.4.2. Evaluation of the results
For all microphone positions two measurements are taken. In
order to compensate for inaccuracies of the measuring equip-
ment, the meter reading is reduced by 1 dB (A), and the
reduced value is taken as the result of measurement. The
results are taken as valid if the difference between the
measurements at one and the same microphone position does
not exceed 2 dB (A).
The highest value measured is taken as the test result. If this
value exceeds the noise limit by 1 dB (A), two additional
measurements are to be taken at the corresponding microphone
position. In this case three out of the four results of measure-
ment thus obtained at that microphone position must have to
comply withth e noise limit.
5.4.3. Limiting value
The sound level shall not exceed the limit of 72 dB (A).1970L0157 — EN — 16.11.1992 — 010.001 — 13
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6. EXTENSION OF EEC TYPE-APPROVAL
6.1. Vehicle typesmodifiedtorunonunleadedpetrol
6.1.1. Approval of a vehicle type modified and/or adjusted solely for
the purpose of making it capable of running on unleaded
petrol, as specified in Directive 85/210/EEC, is extended
when the manufacturer certifies, subject to the approval of the
authority granting type approval, that the sound level for the
modified vehicle shall not exceed the limiting values specified
in item 5.2.2.1.
6.2. Vehicle typesmodifiedforanyotherpurpose
6.2.1. Approval of a vehicle type may be extended to vehicle types
differing with regard to the characteristics listed in Annex III
if the authority granting type approval considers that the modi-
fications made are not likely to have any substantial adverse
effect on the sound level of the vehicle.
7. CONFORMITY OF PRODUCTION
7.1. Every vehicle manufactured following the requirements of this
Directive shall conform to the vehicle type approved, and
satisfy the requirements of section 5.
7.2. In order to verify that the requirements of item 7.1 are met,
adequate monitoring of the production shall be carried out.
7.3. The holder of the approval shall in particular:7.3.1. ensure existence of procedures for the effective control of the
quality of products;
7.3.2. have access to the control equipment necessary for checking
the conformity of each approved type;
7.3.3. ensure that test result data are recorded and that annexed docu-
ments remain available for a period to be determined in
accordance withth e administrative service;
7.3.4. analyze the results of each type of test, in order to verify and
ensure the stability of the product characteristics making allow-
ance for variation of an industrial production;
7.3.5. ensure that for each type of product at least the tests prescribed
in Annex V (I) are carried out;
7.3.6. ensure that any sampling or test pieces giving evidence of non-
conformity with the type of test considered shall give rise to
another sampling and another test. All the necessary steps
must be taken to re-establish the conformity of the corre-
sponding production.
7.4. The competent authority which has granted type-approval may
at any time verify the conformity control method applicable to
eachproduction unit.
7.4.1. At every inspection the test books and production survey
records must be presented to the visiting inspector.
7.4.2. The inspector may take samples at random which will be tested
in the manufacturer's laboratory. The minimum number of
samples may be determined according to the results of the
manufacturer's own verification.
7.4.3. When the quality level appears unsatisfactory or when it seems
necessary to verify the validity of the tests carried out in appli-
cation of item 7.4.2 the Inspector must select samples to be
sent to the technical service which has conducted the type
approval tests.
7.4.4. The competent authority may carry out any test prescribed in
Annex I.
7.4.5. The normal frequency of inspections by the competent
authority is one every two years. If unsatisfactory results are
recorded during one of these visits, the competent authority
must ensure that all necessary steps are taken to re-establish
the conformity of production as rapidly as possible.1970L0157 — EN — 16.11.1992 — 010.001 — 14
▼M8
Figure 1
Microphonepositionsforthemeasurementofamovingvehicle
1970L0157 — EN — 16.11.1992 — 010.001 — 15
▼M8
Figure 2
Testsiteandmicrophonepositionsforthemeasurementofastationaryvehicle
All distances are given in metres
1970L0157 — EN — 16.11.1992 — 010.001 — 16
▼M8
Figure 3
Testapparatusforconditioningbypulsation
1970L0157 — EN — 16.11.1992 — 010.001 — 17
▼M8
Figure 4
Microphonepositionsformeasurementofcompressedairnoise
The measurement is performed on the stationary vehicle according to Figure 4, using two microphone positions at a
distance of 7 m from the contour of the vehicles, and at 1,2 m above the ground.1970L0157 — EN — 16.11.1992 — 010.001 — 18
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ANNEX II
EEC TYPE-APPROVAL OF EXHAUST SYSTEMS AS SEPARATE
TECHNICALUNITS(REPLACEMENTEXHAUSTSYSTEMS)
0. SCOPE
This Annex applies to the type-approval, as separate technical
units within the meaning of Article 9a of Directive 70/156/
EEC, of exhaust systems or components thereof to be fitted to
one or more given types of motor vehicle in categories M1and
N1as replacement parts.
1. DEFINITIONS
1.1. Replacement exhaust system or component thereof means any
part of the exhaust system defined in section 1.2.1 of Annex I
intended to replace on a vehicle a part of the type granted EEC
type-approval with the vehicle in accordance with Annex I.
2. APPLICATION FOR EEC TYPE-APPROVAL
2.1. Application for ECC type-approval in respect of a replacement
exhaust system or component thereof as a separate technical
unit must be submitted by the vehicle manufacturer, the manu-
facturer of the separate technical unit in question or by their
authorized representatives.
2.2. Application for EEC type-approval in respect of eachtype of
replacement exhaust system or component thereof must be
accompanied by the undermentioned document in triplicate
and the following information:
2.2.1. — a description of the type(s) of vehicle to which the system
or components thereof are to be fitted with reference to the
characteristics mentioned in item 1.1 of Annex I. The numbers
and/or symbols designating the engine and vehicle type must
be indicated,
2.2.2. — a description of the replacement exhaust system indicating
the relative position of each system component, together with
mounting instructions,
2.2.3. — detailed drawings of each 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 of the technical service concerned, the applicant
must submit:
2.3.1. — two examples of the system in respect of which application
for EEC type-approval has been made,
2.3.2. — an exhaust system of the type originally fitted to the vehicle
when EEC type-approval was granted,
2.3.3. — a vehicle representative of the 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 section
5.2.2.1 of Annex I(1) and does not exceed by more than 3
dB (A) the values obtained during the type-approval,
and
— 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 of vehicle
described above.
2.4. Before granting type approval the competent authority must
verify the existence of satisfactory arrangements for ensuring
effective control of the conformity of production.1970L0157 — EN — 16.11.1992 — 010.001 — 19
(1) As prescribed in the version of this Directive applicable to vehicle type-approval.
▼M8
3. MARKINGS
3.1. The replacement exhaust system or its components, excluding
fixing hardware and pipes must bear:
3.1.1. — the trademark or trade name of the manufacturer of the
replacement system and its components,
3.1.2. — the manufacturer's trade description,3.1.3. — the EEC type-approval number.3.2. These marks must be clearly legible and indelible, even when
the system is fitted to the vehicle.
4. EEC TYPE-APPROVAL
4.1. If an application within the meaning of 2.1 is approved, the
competent authority must draw up a certificate corresponding
to the model shown in Annex IV. The type-approval number
must be preceded by the distinctive letter(s) of the country
granting EEC type-approval.
5. SPECIFICATIONS
5.1. General specifications
5.1.1. The replacement exhaust systems or component thereof must
be designed, constructed and capable of being mounted so as
to ensure that the vehicle complies with the provisions of this
Directive under normal conditions of use, notwithstanding any
vibrations to which it may be subject.
5.1.2. The exhaust system or components thereof must be designed,
constructed and capable of being mounted so that reasonable
resistance to the corrosion phenomena to which it/they is/are
exposed is obtained having regard to the conditions of use of
the vehicle.
5.2. Specificationsrelatingtosoundlevels
5.2.1. The acoustic efficiency of the replacement exhaust system or
component thereof must be checked using the methods
described in sections 5.2.2.4 and 5.2.3.4 of Annex I(
1).
When the replacement exhaust system or component thereof is
mounted on the vehicle referred to in section 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 2.3.3, when this is fitted with an exhaust
system of the same type as that fitted to the vehicle when EEC
type-approval was granted.
5.3. Measurement ofvehicleperformance
5.3.1. The replacement exhaust system or components thereof must
be such as to ensure that vehicle performance is comparable
with that achieved with the original equipment exhaust systemor component thereof.
5.3.2. The replacement exhaust system or, depending on the manufac-
turer'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 2.3.3.
5.3.3. The check must take the form of a measurement of pressure
loss under the conditions specified in 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.1970L0157 — EN — 16.11.1992 — 010.001 — 20
(1) As prescribed in the version of this Directive applicable to vehicle type-approval.
▼M8
5.3.4. Test method
5.3.4.1. Engine test method
The measurement must be conducted on the engine referred to
in 2.3.4 coupled to a dynamometer.
With the throttle completely open, the bench must be so
adjusted as to obtain the engine speed (S) corresponding to
the rated maximum power of the engine.
For the measurement of back 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 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 of back 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
componentsthereoffilledwithfibrousmaterials
Fibrous materials must not be used in the manufacture of repla-
cement exhaust systems or components thereof unless
appropriate measures are taken during the design and produc-
tion stages to ensure that a level of efficiency is attained
corresponding to the limits set out in section 5.2.2.1 of Annex
I.
Sucha 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 5.2.1, when the
exhaust system is tested on a vehicle in accordance with the
methods described in sections 5.2.2 and 5.2.3 of Annex I.
If this condition is not observed, the entire exhaust system
must be subjected to conditioning. This must be done using
one of the three methods described in sections 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 speci-
fied in 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 whichhas been emptied.
6. CONFORMITY OF PRODUCTION
6.1. Any replacement exhaust system or component thereof bearing
an EEC type-approval number pursuant to this Directive must
conform to the approved type of exhaust system and comply
withth e requirements of section 5.
6.2. In order to verify that the requirements of item 6.1 are met,
adequate monitoring of the production shall be carried out.
6.3. The holder of the approval must in particular:6.3.1. ensure the existence of procedures for effective control of the
quality of products;
6.3.2. have access to the testing equipment necessary for checking the
conformity of eachapproved type;1970L0157 — EN — 16.11.1992 — 010.001 — 21
▼M8
6.3.3. ensure that test result data are recorded and that annexed docu-
ments shall remain available for a period to be determined in
agreement withth e administrative service;
6.3.4. analyze the results of each type of test, in order to verify and
ensure the stability of the product characteristics making allow-
ance for variation of an industrial production;
6.3.5. ensure that for each type of product at least the tests prescribed
in Annex V (II) are carried out;
6.3.6. ensure that sampling or test pieces giving evidence of non-
conformity in the type of test in question give rise to a further
sampling and test. All the necessary steps must be taken to
restore conformity of the corresponding production.
6.4. The competent authority which has granted type-approval may
at any time verify the conformity control method applicable to
eachproduction unit.
6.4.1. At every inspection the test books and production survey
records must be presented to the visiting inspector.
6.4.2. The inspector may take samples at random for testing in the
manufacturer's laboratory. The minimum number of samples
may de determined according to the results of the manufac-
turer's own verification.
6.4.3. When the quality level appears unsatisfactory or when it seems
necessary to verify the validity of the tests carried out in appli-
cation of 6.4.2, the inspector must select samples to be sent to
the technical service which has conducted the type approval
tests.
6.4.4. The competent authority may carry out any test prescribed in
Annex I.
6.4.5. The normal frequency of inspections by the competent
authority is one every two years. If unsatisfactory results are
recorded during one of these visits, the competent authority
must ensure that all necessary steps are taken to restore confor-
mity of production as rapidly as possible.1970L0157 — EN — 16.11.1992 — 010.001 — 22
▼M8
Backpressure—measuringpoints
1970L0157 — EN — 16.11.1992 — 010.001 — 23
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ANNEX III
MODEL
Maximum size: A4 (210 × 297 mm)
1970L0157 — EN — 16.11.1992 — 010.001 — 24
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1970L0157 — EN — 16.11.1992 — 010.001 — 25
▼M8
1970L0157 — EN — 16.11.1992 — 010.001 — 26
▼M8
ANNEX IV
MODEL
Maximum size: A4 (210 × 297 mm)
1970L0157 — EN — 16.11.1992 — 010.001 — 27
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1970L0157 — EN — 16.11.1992 — 010.001 — 28
▼M8
ANNEX V
CHECKSONCONFORMITYOFPRODUCTION
I. VEHICLES
1.General
These requirements are consistent with the test to be held to check confor-
mity of production, pursuant to sections 7.3.5 and 7.4.3 of Annex I.
2.Testingprocedures
The methods of testing, measuring instruments and interpretation of results
shall be those described in Annex I. The vehicle(s) under test shall be
subjected to the test for measurement of noise of vehicle in motion as
described in section 5.2.2.4 of Annex I.
3.Sampling
One vehicle has to be chosen. If after the test in 4.1 below the vehicle is
not considered to conform to the requirements of this Directive, two more
vehicles have to be tested.
4.Evaluationoftheresults
4.1. If the sound level of the vehicle tested pursuant to sections 1 and 2 does
not exceed by more than 1 dB (A) the limit values prescribed in item
5.2.2.1 of Annex I, the vehicle type shall be considered to conform to the
requirements of this Directive.
4.2. If the vehicle tested according to 4.1 does not satisfy the requirements laid
down in that section, two more vehicles of the same type must be tested
pursuant to sections 1 and 2.
4.3. If the sound level of the second and/or third vehicle of 4.2 exceeds by more
than 1 dB (A) the limit values prescribed in section 5.2.2.1 of Annex I, the
vehicle type is considered not to conform to the requirements of this Direc-
tive and the manufacturer must take the necessary measures to restore the
conformity.
II. REPLACEMENT EXHAUST SYSTEMS
1.General
These requirements are consistent with the test to be held to check confor-
mity of production, pursuant to sections 6.3.5 and 6.4.3 of Annex II.
2.Testingprocedures
The methods of testing, measuring instruments and interpretation of results
are those described in Annex II. The exhaust system or component under
test must be subjected to the test as described in Annex II, section 5.
3.Sampling
An exhaust system or component has to be chosen. If, after the test in 4.1,
the sample is not considered to conform to the requirements of this Direc-
tive, two more samples have to be tested.
4.Evaluationoftheresults
4.1. If the sound level of the exhaust system or component, tested pursuant to
sections 1 and 2, measured in accordance withsection 5.2 of Annex II,
does not exceed by more than 1 dB (A) the level measured during the
EEC type-approval tests of this type of exhaust system or component, the
exhaust system or component type is considered to conform to the require-
ments of this Directive.
4.2. If the exhaust system or component tested according to 4.1 does not satisfy
the requirements laid down in that section, two more exhaust systems or
components of the same type must be tested pursuant to sections 1 and 2
above.
4.3. If the sound level of the second and/or third sample of 4.2 exceeds by more
than 1 dB (A) the level measured during the EEC type-approval tests of1970L0157 — EN — 16.11.1992 — 010.001 — 29
▼M8
this type of exhaust system or component, the exhaust system or compo-
nent type is considered not to conform to the requirements of this
Directive and the manufacturer must take the necessary measures to restore
the conformity.1970L0157 — EN — 16.11.1992 — 010.001 — 30
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ANNEX VI
TESTTRACKSPECIFICATIONS
This Annex lays down specifications relating to the physical characteristics of
the paving and the layout of the test track paving.
1. REQUIRED CHARACTERISTICS OF THE SURFACE
A surface is considered to conform to this Directive provided that the
texture and voids content or sound absorption coefficient have been
measured and found to fulfill all the requirements given in 1.1 to
1.4 and provided that the design requirements (Section 2.2) have
been met.
1.1.Residualvoidscontent
The residual voids content, Vc, of the test track paving mixture shall
not exceed 8 %. See section 3.1 for measurement procedure.
1.2.Soundabsorptioncoefficient
If the surface fails to comply with the residual voids content require-
ment, the surface is acceptable only if its sound absorption
coefficient, α,is≤0,10. See section 3.2 for measurement procedure.
The requirement of section 1.1. and 1.2. is met also if only sound
absorption has been measured and found to be: α≤0,10.
1.3.Texturedepth
The texture depth (TD) measured according to the volumetric method
(see section 3.3) shall be:
TD≥0,4 mm.
1.4.Homogeneity ofthesurface
Every practical effort shall be taken to ensure that the surface is
made to be as homogenous as possible within the test area. This
includes the texture and voids content, but it should also be observed
that if the rolling process results in more effective rolling at some
places than at others, the texture may be different and uneveness
causing bumps may also occur.
1.5.Period oftesting
In order to check whether the surface continues to conform to the
texture and voids content or sound absorption requirements stipulated
in this standard, periodic testing of the surface shall be done at the
following intervals:
(a) for residual voids content or sound absorption:
— when the surface is new,
— if the surface meets the requirement when new, no further
periodical testing is required.
If it does not meet the requirement when it is new, it may do so
later because surfaces tend to become clogged and compacted
withtime;
(b) for texture depth(TD):
— when the surface is new,
— when the noise testing starts (NB: not before four weeks after
laying),
— then every twelve months.
2. TEST SURFACE DESIGN2.1.Area
When designing the test track layout it is important to ensure that, as
a minimum requirement, the area traversed by the vehicles running
through the test strip is covered with the specified test material with
suitable margins for safe and practical driving. This will require that
the width of the track is at least 3 m and the length of the track1970L0157 — EN — 16.11.1992 — 010.001 — 31
▼M8
extends beyond lines AA and BB by at least 10 m at either end.
Figure 1 shows a plan of a suitable test site and indicates the
minimum area which shall be machine laid and machine compacted
withth e specified test surface material.
Figure 1
Minimumrequirementsfortestsurfacearea
The shaded part is called ‘test area’
2.2.Designrequirementsforthesurface
The test surface shall meet four design requirements:
1. it shall be a dense asphaltic concrete;
2. the maximum chipping size shall be 8 mm (tolerances allow from
6,3 to 10 mm);
3. the thickness of the wearing course shall be ≥30 mm;
4. the binder shall be a straight penetration grade bitumen without
modification.
As a guide to the test surface constructor, an aggregate grading curve
which will give desired characteristics is shown in figure 2. In addi-
tion, table 3 gives some guidelines in order to obtain the desired
texture and durability. The grading curve fits the following formula:
P (% passing) = 100 (d/dmax)½
whered = square meshsieve size, in mm
d
max= 8 mm for the mean curve
dmax= 10 mm for the lower tolerance curve
dmax= 6,3 mm for the upper tolerance curve
In addition to the above, the following recommendations are given:
— the sand fraction (0,063 mm < square mesh sieve size < 2 mm)
shall include no more than 55 % natural sand and at least 45 %
crushed sand,
— the base and sub-base shall ensure a good stability and evenness,
according to best road construction practice,1970L0157 — EN — 16.11.1992 — 010.001 — 32
▼M8
— the chippings shall be crushed (100 % crushed faces) and of a
material with a high resistance to crushing,
— the chippings used in the mix shall be washed,— no extra chippings shall be added on to the surface,— the binder hardness expressed as PEN value shall be 40 to 60, 60
to 80 or even 80 to 100, depending on the climatic conditions of
the country. The rule is that as hard a binder as possible shall be
used, provided this is consistent with common practice,
— the temperature of the mix before rolling shall be chosen so as to
achieve by subsequent rolling the required voids content. In order
to increase the probability of satisfying the specifications of
sections 1.1 to 1.4, the compactness shall be studied not only by
an appropriate choice of mixing temperature, but also by an
appropriate number of passings and by the choice of compacting
vehicle.
Figure 2
Gradingcurveoftheaggregateintheasphalticmix,withtolerances
Table 3
Designguidelines
Target values
TolerancesBy total mass
of mixBy mass of
the apprecate
Mass of stones, Square MeshSieve (SM)>
2m m47,6 % 50,5 % ±5
Mass of sand 0,063 < SM < 2 mm 38,0 % 40,2 % ±5
Mass of filler SM < 0,063 mm 8,8 % 9,3 % ±2
Mass of binder (bitumen) 5,8 % N.A. ±0,5
Maximum chipping size 8 mm 6,3—10
Binder hardness (see below)
Polished stone value (PSV) (see doc. 5 in
bibliography)>5 0
Compactness, relative to Marshall compact-
ness98 %1970L0157 — EN — 16.11.1992 — 010.001 — 33
▼M8
3. TEST METHODS
3.1.Measurementoftheresidualvoidscontent
For the purpose of this measurement, cores have to be taken from the
track at least at four different positions which are equally distributed
in the test area between lines AA and BB (see figure 1). In order to
avoid inhomogeneity and unevenness in the wheel tracks, cores
should not be taken in the wheel tracks themselves, but close to
them. Two cores (minimum) should be taken close to the wheel
tracks and one core (minimum) should be taken approximately
midway between the wheel tracks and each microphone location.
If there is a suspicion that the condition of homogeneity is not met
(see section 1.4), cores shall be taken from more locations within
the test area.
The residual voids content has to be determined for each core. Then
the average value from all cores shall be calculated and compared
with the requirement of section 1.1. In addition, no single core shall
have a voids value which is higher than 10 %.
The test surface constructor is reminded of the problem which may
arise when the test area is heated by pipes or electrical wires and
cores must be taken from this area. Such installations must be care-
fully planned withrespect to future core drilling locations. It is
recommended to leave a few locations of size approximately 200 ×
300 mm where there are no wires or pipes, or where the latter are
located deep enoughin order not to be damaged by cores taken
from the surface layer.
3.2.Soundabsorptioncoefficient
The sound absorption coefficient (normal incidence) shall be
measured by the impedance tube method using the procedure speci-
fied in ISO/DIS 10534: ‘Acoustics — Determination of sound
absorption coefficient and impedance by a tube method’.
Regarding test specimens, the same requirements shall be followed as
regarding the residual voids content (see section 3.1).
The sound absorption shall be measured in the range 400 to 800 Hz
and in the range 800 to 1 600 Hz (at least at the centre frequencies of
third octave bands) and the maximum values shall be identified for
both of these frequency ranges. Then these values, for all test cores,
shall be averaged to constitute the final result.
3.3.Volumetricmacrotexture measurement
For the purposes of this standard, texture depth measurements shall
be made on at least 10 positions evenly spaced along the wheel
tracks of the test strip and the average value taken to compare with
the specified minimum texture depth. See Annex F to Draft Standard
ISO/DIS 10844 for a description of the procedure.
4. STABILITY IN TIME AND MAINTENANCE
4.1.Ageinfluence
In common with many other surfaces, it is expected that the tyre/road
noise levels measured on the test surface may increase slightly during
the first six to 12 months after construction.
The surface will achieve its required characteristics not earlier than
four weeks after construction. The influence of age on the noise
from trucks is generally less than that from cars.
The stability over time is determined mainly by the polishing and
compaction by vehicles driving on the surface. It shall be periodically
checked as stated in section 1.5.
4.2.Maintenanceofthesurface
Loose debris or dust which could significantly reduce the effective
texture depthmust be removed from th e surface. In countries with
winter climates, salt is sometimes used for de-icing. Salt may alter
the surface temporarily or even permanently in such a way as to
increase noise and is therefore not recommended.1970L0157 — EN — 16.11.1992 — 010.001 — 34
▼M8
4.3.Repavingthetestarea
If it is necessary to repave the test track, it is usually unnecessary to
repave more than the test strip (of 3 m width in figure 1) where vehi-
cles are driving provided the test area outside the strip met the
requirement of residual voids content or sound absorption when it
was measured.
5. DOCUMENTATION OF THE SURFACE AND OF TESTS
PERFORMED ON IT
5.1.Documentationofthetestsurface
The following data shall be given in a document describing the test
surface:
(a) the location of the test track;
(b) type of binder, binder hardness, type of aggregate, maximum
theoretical density of the concrete (‘DR’), thickness of the
wearing course and grading curve determined from cores from
the test track;
(c) method of compaction (e.g. type of roller, roller mass, number of
passes);
(d) temperature of the mix, temperature of the ambient air and wind
speed during laying of the surface;
(e) date when the surface was laid and contractor;
(f) all or at least the latest test result, including:
(i) the residual voids content of each core;
(ii) the locations in the test area from where the cores for voids
measurement have been taken;
(iii) the sound absorption coefficient of each core (if measured).
Specify the results both for each core and each frequency
range as well as the overall average;
(iv) the locations in the test area from where the cores for
absorption measurement have been taken;
(v) texture depth, including the number of tests and standard
deviation;
(vi) the institution responsible for tests (i) and (iii) and the type
of equipment used;
(vii) date of the test(s) and date when the cores were taken from
the test track.
5.2.Documentationofvehicle noisetestsconductedonthesurface
In the document describing the vehicle noise test(s) it shall be stated
whether all the requirments were fulfilled or not. Reference shall be
given to a document according to section 5.1.1970L0157 — EN — 16.11.1992 — 010.001 — 35