GB/T 3449-2026 Active

This document specifies the measurement methods and conditions for the internal noise levels of railway vehicles or other track-based vehicles, with the aim of obtaining reproducible measurement results, excluding track maintenance vehicles in operation. This document applies to: -- type testing; -- periodic supervision inspections; -- routine noise measurements. This document does not apply to the monitoring or evaluation of noise exposure to passengers or drivers, nor to rubber-tyred guided vehicles. This document provides methods for measuring internal noise in vehicles under the following conditions (typically, only some test items are selected for vehicle type testing): -- when the vehicle is running at a constant speed; -- when the vehicle is stationary; -- when the vehicle is accelerating or decelerating; -- in the driver's cab during external whistle sounding. This document does not provide measurement methods for: -- the audibility or intelligibility of any audible signals; -- the evaluation of sound warning devices other than whistles or electric sirens. This document does not address the evaluation of noise exposure to crew members due to their working environment. The results can be used for: -- characterizing the internal noise characteristics of railway and urban rail transit trains; -- comparing the internal noise of various types of vehicles in specific sections; -- obtaining basic sound source data of trains. The measurement methods for type testing are at the engineering level (Level 2, with an accuracy of ±2 dB), which is the preferred level for noise disclosure (see ISO 12001). If the measurement conditions are relaxed, such as conducting monitoring measurements on trains in operation, the results will no longer meet the engineering level. The measurement methods for acceleration and deceleration are at the simplified level (Level 3).