ISO 362-2:2009
(Main)Measurement of noise emitted by accelerating road vehicles — Engineering method — Part 2: L category
Measurement of noise emitted by accelerating road vehicles — Engineering method — Part 2: L category
ISO 362-2:2009 specifies an engineering method for measuring the noise emitted by road vehicles of categories L3, L4 and L5 under typical urban traffic conditions. It excludes vehicles of category L1 and L2, which are covered by ISO 9645, vehicles of categories M and N covered by ISO 362-1 and vehicles of categories L6 and L7. The specifications are intended to reproduce the level of noise generated by the principal noise sources during normal driving in urban traffic, typically on roads with speed limits of 50 km/h and 70 km/h. The method is designed to meet the requirements of simplicity as far as they are consistent with reproducibility of results under the operating conditions of the vehicle. The test method requires an acoustical environment that is only obtained in an extensive open space. Such conditions are usually provided for type approval measurements of a vehicle, measurements at the manufacturing stage and measurements at official testing stations.
Mesurage du bruit émis par les véhicules routiers en accélération — Méthode d'expertise — Partie 2: Catégorie L
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 362-2
First edition
2009-07-15
Measurement of noise emitted by
accelerating road vehicles — Engineering
method —
Part 2:
L category
Mesurage du bruit émis par les véhicules routiers en accélération —
Méthode d'expertise —
Partie 2: Catégorie L
Reference number
©
ISO 2009
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ii © ISO 2009 – All rights reserved
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 2
3 Terms and definitions. 2
4 Symbols and abbreviated terms . 6
5 Specification of the acceleration for vehicles of category L3 with PMR > 25 . 7
5.1 General. 7
5.2 Calculation of acceleration . 7
5.3 Calculation of the target acceleration. 8
5.4 Calculation of the reference acceleration . 9
5.5 Partial power factor k . 9
P
6 Instrumentation. 9
6.1 Instruments for acoustical measurement .9
6.2 Instrumentation for engine and vehicle speed measurements. 10
6.3 Meteorological instrumentation . 10
7 Acoustical environment, meteorological conditions and background noise . 10
7.1 Test site . 10
7.2 Meteorological conditions . 11
7.3 Background noise. 12
8 Test procedures . 12
8.1 Microphone positions. 12
8.2 Conditions of the vehicle . 12
8.3 Operating conditions. 13
8.4 Measurement readings and reported values . 16
8.5 Measurement uncertainty . 17
9 Test report . 18
Annex A (informative) Technical background for development of vehicle noise test procedure
based on in-use operation in urban conditions . 19
Annex B (informative) Measurement uncertainty — Framework for analysis according to
ISO/IEC Guide 98-3 . 25
Annex C (informative) Flowchart of the procedure for category L3 with PMR > 25 . 28
Annex D (informative) Flowchart for vehicles of category L3 with PMR u 25 . 29
Annex E (informative) Flowchart for vehicles of categories L4 and L5. 30
Annex F (informative) Indoor test operation. 31
Bibliography . 34
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 362-2 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise.
This first edition of ISO 362-2, together with ISO 362-1, cancels and replaces ISO 362:1998 and
ISO 7188:1994, which have been technically revised.
ISO 362 consists of the following parts, under the general title Measurement of noise emitted by accelerating
road vehicles — Engineering method:
⎯ Part 1: M and N categories
⎯ Part 2: L category
iv © ISO 2009 – All rights reserved
Introduction
From as early as 1994, the International Motorcycle Manufacturers Association (IMMA) has collected in-use
data for vehicles of category L3 (two-wheeled motorcycles) to study motorcycle dynamics, rider attitude and
behaviour. In 1999 and 2000, additional in-use data was collected through a tripartite project in which the
Dutch Ministry of the Environment (VROM), the Dutch research institute TNO-Automotive and the IMMA took
part. This project eventually led to the adoption of the Worldwide Motorcycle Exhaust Emission Test Cycle
(WMTC) as a UNECE Global Technical Regulation under the 1998 Agreement (Agreement concerning the
establishing of global technical regulations for wheeled vehicles, equipment and parts which can be fitted
and/or be used on wheeled vehicles).
Though the aim of the WMTC project was to collect data with which to construct an exhaust emissions test
cycle for motorcycles, the in-use data was equally suitable as a basis for the definition of a more
representative and performance-based urban noise test procedure. From 2002 to 2004, additional in-use data
for low-performance motorcycles was added to ensure the representativity of the in-use database for small
engine displacement motorcycles. Additional wide-open-throttle acceleration data from large engine
displacement motorcycles was collected in the course of 2005 to upgrade the acceleration equations. Prior to
preparation of this part of ISO 362, an extensive test programme was conducted to verify the practicability and
technical accuracy of the new noise test.
This noise test was developed in accordance with the following set of demands:
⎯ performance-based concept with prescribed acceleration rate prescriptions related to vehicle acceleration
capability and engine speed corresponding to typical motorcycle usage in urban and conurban areas, i.e.
where motorcycles are in closest proximity to the greater part of the population — this typically relates to
motorcycle usage on roads with speed limits of 50 km/h and 70 km/h;
⎯ accurate simulation of noise source distribution (intake, exhaust, engine/gearbox …) in relation to the
most relevant motorcycle operations;
⎯ comparability with other vehicle types in the same operating environment;
⎯ independency of vehicle design to allow future propulsion technologies to be tested.
The procedure uses two operating conditions, i.e. a wide-open-throttle acceleration phase and a constant
speed phase, to simulate real-life partial throttle acceleration actually used in urban traffic. The combination of
these two primary operating conditions was demonstrated to be equivalent in terms of noise generation to the
partial throttle and partial power (engine load) acceleration. Both primary operating conditions are also more
repeatable and reproducible than partial throttle/power acceleration.
The measurement procedure for categories L4 and L5, already contained in ISO 362:1998, is retained until in-
use data for these categories that suggests the need for change becomes available.
Categories L6 and L7, previously not covered in ISO 362:1998, are excluded pending in-use data becoming
available and thereby allowing a representative test procedure to be considered.
INTERNATIONAL STANDARD ISO 362-2:2009(E)
Measurement of noise emitted by accelerating road vehicles —
Engineering method —
Part 2:
L category
1 Scope
This part of ISO 362 specifies an engineering method for measuring the noise emitted by road vehicles of
categories L3, L4 and L5 under typical urban traffic conditions. It excludes vehicles of category L1 and L2,
which are covered by ISO 9645, vehicles of categories M and N covered by ISO 362-1 and vehicles of
categories L6 and L7.
The specifications are intended to reproduce the level of noise generated by the principal noise sources
during normal driving in urban traffic, typically on roads with speed limits of 50 km/h and 70 km/h (see
Annex A).
The method is designed to meet the requirements of simplicity as far as they are consistent with
reproducibility of results under the operating conditions of the vehicle.
The test method requires an acoustical environment that is only obtained in an extensive open space. Such
conditions are usually provided for
⎯ type approval measurements of a vehicle,
⎯ measurements at the manufacturing stage, and
⎯ measurements at official testing stations.
NOTE 1 The results obtained by this method give an objective measure of the noise emitted under the specified test
conditions. It is necessary to consider the fact that the subjective appraisal of the noise annoyance of different classes of
motor vehicles is not simply related to the indications of a sound measurement system. As annoyance is strongly related
to personal human perception, physiological human conditions, culture and environmental conditions, there is a large
variation and it is therefore not useful as a parameter to describe a specific vehicle condition.
NOTE 2 Spot checks of vehicles chosen at random are rarely made in an ideal acoustical environment. If
measurements are carried out on the road in an acoustical environment which does not fulfil the requirements stated in
this International Standard, the results obtained can deviate appreciably from the results obtained using the specified
conditions.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 4106, Motorcycles — Engine test code — Net power
ISO 6726, Mopeds and motorcycl
...
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