The Ministry of Transport is drafting National Technical Regulations on automobiles, trailers, and semi-trailers participating in road traffic. The regulations are expected to take effect from January 1, 2025.
According to this set of standards, the standards for horns are specified as follows:
The test method is to honk the horn and observe, combined with listening to the sound of the horn.
Evaluation criteria are as follows:
The sound is continuous and the volume is stable.
Normal control, correct installation.
The inspector checks the horn volume as follows:
The test method is to use a volume meter to check if the horn volume is too low or too high: place the microphone of the measuring device close to the longitudinal median plane of the vehicle with a height between 0.5m and 1.5m and 7m from the front of the vehicle.
Evaluation criteria are as follows:
Not less than 87 dB(A), not greater than 112 dB(A)
In addition, the noise level criteria of cars are as follows:
The testing method is to step on the gas to reach 75% of the engine's maximum capacity. If the noise is too loud, check the noise level of the vehicle parked at the tail of the exhaust pipe using equipment according to the measurement method stated in TCVN 7880.
Evaluation criteria are as follows:
The average noise level after calibration shall not exceed the following limits:
Cars, trucks, special-purpose vehicles and light passenger cars, three-wheeled vehicles, and motorized cyclos with a total mass G ≤ 3500 kg: 103 dB(A).
Trucks, special-purpose vehicles and passenger cars with total mass G > 3500 kg and maximum useful engine power P ≤ 150 (kW): 105 dB(A).
Trucks, special-purpose vehicles and passenger cars with total mass G > 3500 kg and maximum useful engine power P > 150 (kW): 107 dB(A).
Crane trucks and special purpose road vehicles: 110 dB(A).
