GB/T 42703-2023 English PDF (GBT42703-2023)

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GB/T 42703-2023: Cycles -- Audible warning devices -- Technical specification and test methods
GB/T 42703-2023
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 43.150
CCS Y 14
GB/T 42703-2023 / ISO 14878:2015
Cycles - Audible warning devices - Technical specification
and test methods
(ISO 14878:2015, IDT)
ISSUED ON: MAY 23, 2023
IMPLEMENTED ON: DECEMBER 01, 2023
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 5
4 Symbols and abbreviations ... 5
5 Measuring instruments ... 5
5.1 Acoustic measuring instrument ... 5
6 Acoustic environment, meteorological conditions and background noise ... 7
6.1 Test site ... 7
6.2 Meteorological conditions ... 8
6.3 Background noise ... 8
6.4 AWD installation ... 8
6.5 Microphone and AWD location ... 8
7 Measurement of sound pressure level ... 9
7.1 AWD operation ... 9
7.2 Measurement readings and reported values ... 9
7.3 Sound pressure requirements ... 9
7.4 Low battery indication ... 10
8 Durability test ... 10
8.1 Test steps ... 10
8.2 Test results ... 11
9 Test report ... 11
10 Marks ... 12
Cycles - Audible warning devices - Technical specification
and test methods
1 Scope
This document specifies the technical specifications for audible warning devices
installed on cycles, such as sound pressure levels and durability performance. It also
describes the corresponding test methods.
This document applies to various types of audible warning devices for cycles.
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 9227, Corrosion test in artificial atmosphere - Salt spray tests
NOTE: GB/T 10125-2021, Corrosion tests in artificial atmospheres -- Salt spray tests (ISO
9227:2017, MOD)
ISO 26101, Acoustics - Test methods for qualification of free field environments
NOTE: GB/T 34828-2017, Acoustics -- Test methods for the qualification of free-field
environments (ISO 26101:2012, IDT)
IEC 60942, Electroacoustics - Sound calibrators
NOTE: GB/T 15173-2010, Electroacoustics -- Sound calibrators (IEC 60942:2003, IDT)
IEC 61672-1, Electroacoustics - Sound level meters – Part 1: Specifications
NOTE: GB/T 3785.1-2010, Electroacoustics -- Sound level meters -- Part 1: Specifications (IEC
61672-1:2002, IDT)
IEC 61672-3, Electroacoustics - Sound level meters - Part 3: Periodic tests
NOTE: GB/T 3785.3-2018, Electroacoustics -- Sound level meters -- Part 3: Periodic tests (IEC
61672-3:2013, IDT)
The entire measurement system shall be checked using a Class 1 acoustic calibrator
complying with the requirements of IEC 60942.
When measuring, acoustic measuring instruments with "F" time weighting and "A"
frequency weighting described in IEC 61672-1 shall be used. When using a system that
monitors A-weighted sound pressure levels at periodic intervals, the interval between
readings shall not be greater than 30 ms.
Instruments shall be maintained and calibrated in accordance with the instrument
manufacturer's instructions.
When it is impossible to make an overall judgment or conclusion on whether the sound
level meter complies with all the specifications of IEC 61672-1, the sound level meter
or equivalent measurement system shall at least meet the requirements of Class 1 sound
level meter in IEC 61672-3.
NOTE: The tests in IEC 61672-3 only cover part of the provisions of IEC 61672-1. IEC 61672-1
covers a large range (temperature range, frequency requirements up to 20 kHz, electromagnetic
compatibility test), so from an economic perspective, it is impossible to verify each parameter of
the computer data acquisition system one by one according to the requirements of IEC 61672-1.
5.1.2 Calibration
At the beginning and end of each measurement, the entire acoustic measurement system
shall be checked with the acoustic calibrator described in 5.1.1. Without additional
adjustments, the difference between readings shall not be greater than 0.5 dB. If this
value is exceeded, measurements taken after the last satisfactory inspection shall be
discarded.
5.1.3 Compliance requirements
The acoustic calibrator shall be calibrated once a year in accordance with the
requirements of IEC 60942.
The instrument system shall be calibrated at least once every 2 years in accordance with
the requirements of IEC 61672-3.
All compliance testing shall be performed by an authorized laboratory traceable to an
appropriate reference.
5.1.4 Meteorological instrument
Meteorological instruments used to monitor environmental conditions during the test
shall meet the following technical specifications:
a) Temperature measuring device ±1°C or less;
b) Wind speed measuring device ±1.0 m/s;
c) Air pressure measuring device ±5 hPa;
d) Relative humidity measuring device ±5%.
6 Acoustic environment, meteorological conditions and
background noise
6.1 Test site
AWD shall be tested in an anechoic environment. It can also be conducted in a semi-
anechoic room or an open field. When testing in an open field, precautions shall be
taken (for example, erecting a set of sound-absorbing panels) to block the echo from
the ground in the measurement area.
Using the following evaluation criteria and measurement requirements that are close to
those recommended by ISO 26101, the test facilities shall be able to meet the
requirements of ISO 26101.
a) The site considered as anechoic shall be at least a hemispheric space with a radius
of 5 m.
b) The test sound source shall be placed in the center of the area considered anechoic,
i.e., on the ground.
c) The horizontal axis of the microphone shall be on the line connecting the center
of the sound source to the position of the microphone.
d) The maximum spacing between measuring points shall depend on the size of the
anechoic site. The spatial resolution of the measurements is at least 10 points.
e) The evaluation bandwidth shall be selected to cover the frequency range of the
typical spectral characteristics of the sound source under test. If there is no other
information, it is recommended to be 100 Hz~10000 Hz.
f) The test sound source shall be broadband noise. A 1/3 octave band filter is used
during measurement.
For indoor test sites, the cutoff frequency of the test facility shall be lower than the
frequency of the lowest component of sound emitted during the AWD test.
There shall be no obstacles near the microphone that may affect the sound field. There
shall be no people between the microphone and the sound source. The instrument
observer shall be positioned so as not to affect instrument readings.
NOTE: Users of this document are aware that measurements are only valid if the cutoff frequency
ground.
The reference direction under free field conditions (see IEC 61672-1) shall be
horizontal and pointed vertically towards the center of the AWD.
The microphone shall be located 2 m ± 0.01 m from the center of the AWD.
7 Measurement of sound pressure level
7.1 AWD operation
The AWD being tested shall be sounded by the operator operating (pushing, pulling,
pressing) the controls in accordance with the manufacturer's requirements. The position
of the operator shall not have a signi...