GB/T 38694-2020 English PDF (GBT38694-2020)

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GB/T 38694-2020: Requirements and test methods of alert for vehicle turning right
GB/T 38694-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 43.020
T 09
Requirements and Test Methods of Alert for Vehicle
Turning Right
ISSUED ON: MARCH 31, 2020
IMPLEMENTED ON: OCTOBER 1, 2020
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 ... 4 
4 Requirements ... 5 
5 Test Methods ... 7 
Requirements and Test Methods of Alert for Vehicle
Turning Right
1 Scope
This Standard specifies the terms and definitions, requirements and test methods of
alert for vehicle turning right.
This Standard is applicable to alert device for vehicle turning right, and trucks installed
with the device, and with the maximum design total mass greater than or equal to
12,000 kg. Other vehicles may take this as a reference in the implementation.
2 Normative References
The following documents are indispensable to the application of this document. In
terms of references with a specified date, only versions with a specified date are
applicable to this document. In terms of references without a specified date, the latest
version (including all the modifications) is applicable to this document.
GB/T 3241-2010 Electroacoustics - Octave-band and Fractional-octave-band Filters
(IEC 61260:1995, MOD)
GB/T 3785.1-2010 Electroacoustics - Sound Level Meters - Part 1: Specifications (IEC
61672-1:2002, IDT)
3 Terms and Definitions
The following terms and definitions are applicable to this document.
3.1 Alert for Vehicle Turning Right
Alert for vehicle turning right refers to the sound that a vehicle emits to the right area
when turning right, which can prompt other road users.
NOTE: alert for vehicle turning right is abbreviated as alert in this Standard.
3.2 Alert Device for Vehicle Turning Right
Alert device for vehicle turning right refers to a device installed in a specified area of
the vehicle and can emit a prompt tone as required.
NOTE: alert device for vehicle turning right is abbreviated as alert device in this Standard.
4.3.2 The conversion between the daytime working mode and the nighttime working
mode may be manually or automatically implemented.
4.3.3 The alert device shall be reasonably installed on the vehicle and satisfy the
following requirements:
a) The alert device shall be installed on the right side of the vehicle, 2.5 m
backward from the centerline of the first axis to the front end of the vehicle;
the maximum sound pressure level of the device shall face towards the right
side of the vehicle. The installation and connection shall be firm and reliable.
b) When the right turn signal is triggered, the alert shall be emitted in time; during
the right-turn process, the alert shall be continuous; after the right-turn signal
disappears, the alert shall continue for no less than 1 complete cycle.
c) When hazard warning signal is used, the alert device shall not work.
d) When the alert device fails, it shall not affect the normal use of the vehicle.
e) When the vehicle speed is greater than 40 km/h, the alert device may stop
working. If the vehicle can automatically recognize lane changing or turning
state, wen the vehicle changes to another lane, the alert device may stop
working.
5 Test Methods
5.1 Alert Device Test
5.1.1 Test conditions
5.1.1.1 Measurement site
Anechoic room or semi-anechoic room; the background noise is ≤ 40 dB(A). Except
for special requirements, the ambient temperature of the test is 23 °C ± 5 °C.
5.1.1.2 Measurement instrument
When carrying out 1/3 octave measurement, the measurement instrument shall comply
with the stipulations of Level-1 filter in GB/T 3241-2010. The used sound level meter
or other equivalent measurement instruments shall comply with the stipulations of
Level-1 instrument in GB/T 3785.1-2010. During the measurement, the “A” frequency
weighting characteristics and “F” time weighting characteristics described in GB/T
3785.1-2010 shall be used. When a system that can periodically monitor the A-
weighted sound level is used, the time interval of the readings shall be not greater than
30 ms. In terms of buzzer voice combination alert, the measurement instrument shall
be able to respectively measure the sound pressure level of the buzzer and the voice
voice combination alert. Respectively measure the sound pressure level of the buzzer
alert and the voice alert. For each alert, measure three times. The difference among
the measurement results shall not exceed 2 dB(A). Take the average of the three
measurement results respectively as the final measurement result of the buzzer alert
and voice alert; compare them and the result shall comply with the stipulations of 4.2.2.
5.1.4 Frequency rate and frequency measurement
5.1.4.1 Under the conditions specified in 5.1.1, measure the frequency rate of the
buzzer. The result shall comply with the stipulations of 4.2.1.
5.1.4.2 Under the conditions specified in 5.1.1, measure the frequency of the alert; the
total duration of the measurement shall be not less than 3 min. If the last cycle is an
incomplete cycle, it shall also be counted as one cycle. The result shall comply with
the stipulations of 4.2.1.
5.2 Complete-vehicle Alert Test
5.2.1 Test conditions
5.2.1.1 Measurement site
Flat open ground composed of concrete, dense asphalt or similar hard materials
without obvious pores. Avoid conducting the measurement on snowfield, haystacks,
loose soil or other grounds with sound absorption characteristics. Within 10 m from the
sound level meter of the vehicle to be tested, there shall be no large reflectors, such
as: vehicles, buildings, billboards, trees, parallel walls and people, etc.
5.2.1.2 Meteorological conditions
The weather shall manifest NO snow, rain or fog. The wind speed (including gusts)
shall be not greater than 5 m/s. When the wind speed exceeds 2 m/s, it is
recommended that the sound level meter shall use a windshield. During the test, the
ambient temperature range is -10 °C ~ 50 °C; it shall also comply with the stipulations
of 6.3.1 in GB/T 3785.1-2010.
5.2.1.3 Background noise
During the measurement, the background noise (A-weighted sound pressure level) is
at least 10 dB(A) lower than the alert being measured.
5.2.1.4 Measurement instrument
The used sound level meter or other equivalent measurement instruments, including
the windshields, shall comply with the stipulations of Level-1 instruments in GB/T
3785.1-2010. During the measurement, the “A” frequency weighting characteristics
and “F” time weighting characteristics described in GB/T 3785.1-2010 shall be used.