ISO 14878:2015

INTERNATIONAL ISO
STANDARD 14878
First edition
2015-12-15
Cycles — Audible warning devices
— Technical specification and test
methods
Cycles — Dispositifs avertisseurs sonores — Spécifications techniques
et méthodes d’essai
Reference number
©
ISO 2015
© ISO 2015, Published in Switzerland
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ii © ISO 2015 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 2
5 Instrumentations . 2
5.1 Instruments for acoustical measurement. 2
5.1.1 General. 2
5.1.2 Calibration . 2
5.1.3 Compliance with requirements . 2
5.1.4 Meteorological Instrumentation . 2
6 Acoustical environment, meteorological conditions, and background noise .3
6.1 Test site . 3
6.2 Meteorological conditions . 3
6.3 Background noise . 3
6.4 Mounting of the AWD . 4
6.5 Microphone and AWD positions . 4
7 Measurement of the sound pressure level . 4
7.1 Actuation of the AWD . 4
7.2 Measurement readings and reported values . 4
7.2.1 General. 4
7.2.2 Data compilation . 4
7.3 Required sound pressure . 5
7.4 Low battery indicator. 5
8 Test of durability . 5
8.1 Test procedure . 5
8.1.1 Stability mechanical test . 5
8.1.2 Corrosion test . 6
8.2 Test result . 6
9 Test report . 6
10 Marking . 6
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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
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constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 149, Cycles, Subcommittee SC 1, Cycles and
major sub-assemblies.
iv © ISO 2015 – All rights reserved

INTERNATIONAL STANDARD ISO 14878:2015(E)
Cycles — Audible warning devices — Technical
specification and test methods
1 Scope
This International Standard lays down the technical specifications, such as the sound pressure level
and the durability, and specifies the corresponding test method for audible warning devices (AWD)
which may be fitted to cycles.
This International Standard applies to all types of audible warning devices (AWD) for use on bicycles.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 9227, Corrosion test in artificial atmosphere — Salt spray tests
ISO 26101, Acoustics — Test methods for the qualification of free-field environments
IEC 60942, Electroacoustics — Sound calibrators
IEC 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications
IEC 61672-3, Electroacoustics — Sound level meters — Part 3: Periodic tests
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
cycle
any vehicle that has at least two wheels and is propelled solely or mainly by the muscular energy of the
person on that vehicle, in particular by means of pedals
3.2
bicycle
two-wheeled cycle
3.3
audible warning device
AWD
device designed for the purpose to warn people by an audible signal
Note 1 to entry: Including all types of technologies (i.e. bells, horns, electronic audible warning device).
3.4
audible warning device class I
AWD designed for general purpose
3.5
audible warning device class II
AWD designed for purpose of use in area primarily shared by pedestrians and cyclists, such as a
pedestrian zone
4 Symbols and abbreviated terms
AWD Audible warning device
5 Instrumentations
5.1 Instruments for acoustical measurement
5.1.1 General
The apparatus used for measuring the sound pressure level shall be a sound level meter or equivalent
measurement system meeting the requirements of class 1 instruments (inclusive of the recommended
windscreen, if used). These requirements are described in IEC 61672-1.
The entire measurement system shall be checked by means of a sound calibrator that fulfils the
requirements of class 1 sound calibrators according to IEC 60942.
Measurements shall be carried out using the time weighting “F” of the acoustic measurement
instrument and the “A” frequency weighting curve also described in IEC 61672-1. When using a system
that includes a periodic monitoring of the A-weighted sound pressure level, a reading should be made at
a time interval not greater than 30 ms.
The instruments shall be maintained and calibrated in accordance to the instructions of the instrument
manufacturer.
When no general statement or conclusion can be made about conformance of the sound level meter
model to the full specifications of IEC 61672-1, the apparatus used for measuring the sound pressure
level shall be a sound level meter or equivalent measurement system meeting the requirements of
class 1 instruments as described in IEC 61672-3.
NOTE The tests of IEC 61672-3 cover only a limited subset of the specifications in IEC 61672-1 for which
the scope is large (temperature range, frequency requirements up to 20 kHz, EMC tests). It is economically
impossible to verify the whole IEC 61672-1 standard requirements one each item of a computerized data
acquisition systems model.
5.1.2 Calibration
At the beginning and at the end of every measurement session, the entire acoustic measurement system
shall be checked by means of a sound calibrator as described in 5.1.1. Without any further adjustment,
the difference between the readings shall be less than or equal to 0,5 dB. If this value is exceeded, the
results of the measurements obtained after the previous satisfactory check shall be discarded.
5.1.3 Compliance with requirements
Compliance of the sound calibrator with the requirements of IEC 60942 shall be verified once a year.
Compliance of the instrumentation system with the requirements of IEC 61672-3 shall be verified at
least every two years.
All compliance testing shall be conducted by a laboratory which is authorized to perform calibrations
traceable to the appropriate standards.
5.1.4 Meteorological Instrumentation
The meteorological instrumentation used to monitor the environmental conditions during the test
shall meet the following specifications:
— ±1 °C or less for a temperature measuring device;
2 © ISO 2015 – All rights reserved

— ±1,0 m/s for a wind speed-measuring device;
— ±5 hPa for a barometric pressure measuring device;
— ±5 % for a relative humidity measuring device.
6 Acoustical environment, meteorological conditions, and background noise
6.1 Test site
The AWD shall be tested in an anechoic environment. Alternatively, it may be tested in a semi anechoic
chamber or in an open space. In this case, precautions shall be taken to avoid reflections from the
ground within the measuring area (for instance, by erecting a set of absorbing screens).
The test facility shall meet requirements of ISO 26101 with the following qualification criteria and
measurement requirement appropriate to this test method as recommended by ISO 26101:
— space to be deemed anechoic shall be at least a 5-metre radius volume;
— test sound source location shall position in the m
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