声学 - 固定道路车辆发出的声压级的测量

[中文适用范围]： 本文件规定了在静止条件下测量道路车辆外部声压级的测试程序、环境和仪器，提供在发动机转速范围内的声压级的连续测量。 本文件仅适用于配备内燃机的 L、M 和 N 类道路车辆。 当车辆处于静止状态时内燃机无法运行的车辆不属于本文件的范围。 该方法旨在满足简单性的要求，只要它们与车辆运行条件下结果的再现性一致即可。 在车辆型式核准测量期间测量静态 A 计权声压级属于本文件的范围； ——制造阶段的测量； ——在官方测试站进行的测量； ——路边测试的测量。 该文件详细说明了一种测试方法来确定参考声级，该参考声级对于车辆来说是唯一的，因此不适合与一般限制进行比较，因为测试条件、麦克风条件相对于声源的位置可能会有很大变化。 与交通中的实际操作条件相比，我们特意选择了接近且发动机转速明显更高的测试条件，以便能够在更高的背景条件下进行使用中测试，这对于路边检查来说是典型的。 技术背景信息见附件 A。 [外文原描述]： This document specifies a test procedure, environment and instrumentation for measuring the exterior sound pressure levels from road vehicles under stationary conditions, providing a continuous measure of the sound pressure level over a range of engine speeds. This document applies only to road vehicles of categories L, M, and N equipped with internal combustion engines. Vehicles where an internal combustion engine cannot operate when the vehicle is at stationary conditions are outside the scope of this document. The method is designed to meet the requirements of simplicity as far as they are consistent with reproducibility of results under the operating conditions of the vehicle. It is within the scope of this document to measure the stationary A-weighted sound pressure level during — type approval measurements of vehicle; — measurements at the manufacturing stage; — measurements at official testing stations; — measurements at roadside testing. This document specifices a test method to determine a reference sound level which is unique for the vehicle and therefore not suitable to compare against a general limit, as test condition, microphone condition location relative to the sound sources can vary significantly. The test conditions in proximity and at engine speeds significantly higher compared to real operation conditions in traffic are deliberately chosen to enable in-use tests at higher background conditions, which are typical for road-side checks. Technical background information is given in Annex A.