声学.加速道路车辆发出的噪声的测量.工程方法.第3部分:室内试验M和N类

[中文适用范围]： 本标准规定了采用安装测功机的半电波暗室测量M类和N类道路车辆噪声的工程方法。 这些规范旨在实现半消声室中道路车辆外部噪声测试与 ISO 362-1 中所述的室外测试之间的声学相关性。 本文件提供了室内测试的所有必要规范和程序，以获得与当今型式认证测试中典型的运行间测量变化相当的结果。 本文件提供了一种旨在满足简单性要求的方法，只要它们与车辆运行条件下结果的再现性一致即可。 注 1：通过该方法获得的结果给出了在规定的测试条件下发出的噪声的客观测量。 需要考虑的是，对不同类别机动车辆噪声烦扰性的主观评价并不简单地与声音测量系统的指示相关。 由于烦恼与个人感知、人类生理条件、文化和环境条件密切相关，因此存在很大的变化，因此烦恼不适合作为描述特定车辆状况的参数。 注 2：如果在不满足本文件所述要求的房间中进行测量，则获得的结果可能与使用指定条件时的结果有所不同。 [外文原描述]： This document specifies an engineering method for measuring the noise emitted by road vehicles of categories M and N by using a semi anechoic chamber with a dynamometer installed. The specifications are intended to achieve an acoustical correlation between testing the exterior noise of road vehicles in a semi anechoic chamber and outdoor testing as described in ISO 362-1. This document provides all necessary specifications and procedures for indoor testing to obtain results which are comparable to typical run-to-run variations of measurements in today’s type approval tests. This document provides a method designed to meet the requirements of simplicity as far as they are consistent with the reproducibility of results under the operating conditions of the vehicle. NOTE 1 The results obtained by this method give an objective measure of the noise emitted under the specified conditions of test. It is necessary to consider the fact that the subjective appraisal of the noise annoyance of different classes of motor vehicles is not simply related to the indications of a sound measuring system. As annoyance is strongly related to personal human perception, physiological human conditions, culture, and environmental conditions, there is a large variation and annoyance is therefore not useful as a parameter to describe a specific vehicle condition. NOTE 2 If measurements are carried out in rooms which do not fulfil the requirements stated in this document, the results obtained can deviate from the results using the specified conditions.