ISO 6393:1998

INTERNATIONAL ISO
STANDARD 6393
Second edition
1998-11-15
Acoustics — Measurement of exterior noise
emitted by earth-moving machinery —
Stationary test conditions
Acoustique — Mesurage du bruit émis à l'extérieur par les engins
de terrassement — Conditions d'essai statiques
A
Reference number
ISO 6393:1998(E)

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ISO 6393:1998(E)
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 3.
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.
International Standard ISO 6393 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1,
Noise, in collaboration with ISO/TC 127, Earth moving machinery.
This second edition cancels and replaces the first edition (ISO 6393:1985), which has been technically revised.
Annex A forms a normative part of this International Standard.
©  ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet iso@iso.ch
Printed in Switzerland
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© ISO
ISO 6393:1998(E)
Introduction
This International Standard is a special test code for specific types of earth-moving machinery.
Specific procedures are described in this special test code to enable the sound power emission in a stationary test
to be determined in a manner which is repeatable. Attachments (bucket, dozer, etc.) for the manufacturer's
production version are to be fitted, since this is the configuration most likely to exist when the machine is in actual
use.
This International Standard enables compliance with noise limits to be determined. It can also be used for
evaluation purposes in noise reduction investigations.
An additional special test code is given in ISO 6394. This other special test code is intended to be used to
determine the noise emitted by earth-moving machinery, measured at the operator's position while the machine is
stationary, in terms of the equivalent continuous A-weighted sound pressure level.
Corresponding measurements of exterior noise and noise at the operator's position under dynamic test conditions
are described in ISO 6395 and ISO 6396, respectively.
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INTERNATIONAL STANDARD  © ISO ISO 6393:1998(E)
Acoustics — Measurement of exterior noise emitted by
earth-moving machinery — Stationary test conditions
1 Scope
This International Standard specifies a method for determining the exterior noise emitted by earth-moving
machinery in terms of the A-weighted sound power level while the machine is stationary with the engine operating at
rated speed under no-load conditions.
This International Standard is applicable to the following specific types of earth-moving machinery:
 excavators (hydraulic or rope-operated);
 crawler and wheel tractor-dozers;
 crawler and wheel loaders; and
 backhoe loaders.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 3744:1994, Acoustics — Determination of sound power levels of noise sources using sound pressure —
Engineering method in an essentially free field over a reflecting plane.
ISO 9249, Earth-moving machinery — Engine test code — Net power.
1)
IEC 60651, Sound level meters.
1)
IEC 60804, Integrating-averaging sound level meters.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 3744 and the following apply.
For the convenience of users of this International Standard, some definitions are quoted from ISO 6165:1997.

1)
IEC 60651 and IEC 60804 will be replaced by IEC 61672.
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ISO 6393:1998(E)
3.1
time-averaged A-weighted sound pressure level, L
pAeq,T
A-weighted sound pressure level averaged on an energy basis over the whole measurement period, T
3.2
A-weighted sound power level, L
WA
A-weighted sound power level obtained from time-averaged A-weighted sound pressure levels averaged over the
measurement surface on an energy basis
3.3
excavator
self-propelled machine on crawler, wheels or legs, having an upper structure normally capable of a 360� swing with
mounted equipment, primarily designed for excavating with a bucket, without moving the undercarriage during the
work cycle
NOTE An excavator work cycle normally comprises excavating, elevating, swinging and discharging material.
[ISO 6165:1997]
See Figure 1.
Figure 1 — Excavator
3.4
tractor-dozer
self-propelled crawler or wheeled machine with equipment having either a dozing attachment which cuts, moves
and grades material through forward motion of the machine, or a mounted attachment used to exert a push or a pull
force
[ISO 6165:1997]
See Figure 2.
Figure 2 — Tractor-dozer
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ISO 6393:1998(E)
3.5
loader
self-propelled crawler or wheeled machine, having front-mounted equipment primarily designed for loading
operation (bucket use), which loads or excavates through forward motion of the machine
NOTE A loader work cycle normally comprises filling, elevating, transporting and discharging material.
[ISO 6165:1997]
See Figure 3.
Figure 3 — Loader
3.6
backhoe loader
self-propelled crawler or wheeled machine, having a main frame designed to carry both front-mounted equipment
and rear-mounted backhoe equipment (normally with outriggers); when used in the backhoe mode, the machine is
stationary and normally digs below ground level; when used in the loader mode (bucket use), the machine loads
through forward motion
NOTE A backhoe work cycle normally comprises excavating, elevating, swinging and discharging material. A loader work
cycle normally comprises filling, elevating, transporting and discharging material.
[ISO 6165:1997]
See Figure 4.
Figure 4 — Backhoe loader
4 Instrumentation
The instrumentation shall be capable of carrying out measurements as described in 8.1. The preferred
instrumentation system for acquiring the data is an integrating-averaging sound level meter complying with the
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ISO 6393:1998(E)
requirements of IEC 60804 for a class 1 instrument. Alternative instrumentation, including the microphone and
cable, shall meet the requirements of IEC 60651 for a class 1 instrument.
NOTE The sensitivity to environmental conditions is especially relevant for this type of measurement. It is recommended to
ask the manufacturer for evidence that related tests according to IEC 60651 were carried out with a positive result.
5 Test environment
5.1 General
For the purposes of this International Standard, the test environment specified in ISO 3744:1994, clause 4 and
annex A, applies. Additional requirements are given in 5.2 to 5.6.
5.2 Test site
5.2.1 General
The following two types of test site surface, described in 5.2.2 and 5.2.3, are allowed:
a) hard reflecting plane (concrete or sealed asphalt);
b) combination of hard reflecting plane and sand.
The hard reflecting plane shall be used for testing the following:
 rubber-tyred machines: all modes of operation;
 excavators: all modes of operation;
 crawler loaders: stationary hydraulic mode of operation.
The combination of hard reflecting plane and sand shall be used for testing crawler dozers and crawler loaders with
the machine operating on the sand surface and with the microphone on the hard reflecting plane.
5.2.2 Hard reflecting plane [Test site surface a)]
The test area bordered by the microphones shall consist of concrete or sealed asphalt.
5.2.3 Combination of hard reflecting plane and sand [Test site surface b)]
The travel path on which the machine is placed shall consist of humid sand of grain size up to 2 mm. The minimum
depth of the sand shall be 0,3 m. If 0,3 m is not deep enough for track penetration, the depth shall be increased
accordingly. The surface between the machine and the microphones shall be a hard reflecting plane, as described
in 5.2.2. This provides a reflecting plane rather than an absorptive surface for the measuring environment.
A minimum size combination site can be used by having just a single reflecting plane with a sand path along the
side. In this case, a set of measurements with three microphones shall be carried out on one side of the machine.
Another set shall then be carried out for the other side after turning the machine 180�.
5.3 Test site and environmental correction, K
2
For test site surfaces which consist of a hard reflecting plane, such as concrete or sealed asphalt [5.2.1 a) and b)],
and with no sound-reflecting obstacles within a distance from the source equal to three times the greatest distance
from the source centre to the lower measurement positions (measurement hemisphere radius), it may be assumed
that the environmental correction K is less than or equal to 0,5 dB. It is, therefore, negligible and is disregarded.
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5.4 Background noise
At each meas
...