1.1本指南涵盖了由固定声源（如警报器、固定泵、发电厂或音乐剧场）产生的室外声音的测量。程序描述了测量时该声源的位置、声级、频谱内容和时间特征。用户应注意，风和温度梯度会导致300米（1000英尺）以上的声级发生显著变化。在适当谨慎的情况下，使用本指南得出的测量结果包括但不限于: 1.1.1评估是否符合适用法规， 1.1.2监测降噪计划的有效性， 1.1.3验证缓解噪声影响措施的有效性， 1.1.4验证声音预测模型，以及 1.1.5获取用于声音预测模型的源数据。 1.2本指南可根据指南E 1779和测量计划中的规定使用。 1.2.1本指南也可用于在没有计划的情况下进行测量，前提是操作员/观察员在测量过程中始终具备令执行组织和结果使用者满意的资格，并且符合本指南的适用要求，包括记录保存。 1.3本标准无意解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。 ====意义和用途====== 需要室外声级数据的情况包括但不限于将声级与标准或监管限制进行比较。 本指南提供了以下信息:( 1. )测量室外固定噪声源附近的室外声级，以及( 2. )记录测量所需的其他观察结果。本指南为经过培训的声学专业人员提供了一个标准程序，该程序将产生与中引用的目的一致的结果和文件 1.1.1 - 1.1.5 . 这些声音测量应由在室外声音测量和分析方面经验丰富、熟悉所需设备和技术的使用的人员进行或在其指导下进行。 本指南可供个人、监管机构或其他人用作测量指南，以收集从中引用的约束内的固定声源接收的声级数据 8.1 和 附录X2 . 本指南可用于确定在获得数据的时间、距离和条件下的符合性或不符合性。然而，本指南只是一个测量程序，并没有解决在这些条件、一天中的其他时间、其他距离或与特定标准进行比较的情况下投影获取的数据的问题。特别是，对于给定的声源级，夜间的远处噪声级通常比白天大。

1.1 This guide covers the measurement of outdoor sound due to a fixed sound source such as a siren, stationary pump, power plant, or music amphitheater. Procedures characterize the location, sound level, spectral content, and temporal characteristics of that sound source at the time of measurement. Users should be aware that wind and temperature gradients can cause significant variations in sound levels beyond 300 m (1000 ft). With appropriate caution, the use of measurements resulting from this guide include but are not limited to: 1.1.1 Assessing compliance with applicable regulations, 1.1.2 Monitoring the effectiveness of a noise reduction plan, 1.1.3 Verifying the effectiveness of measures for mitigation of noise impact, 1.1.4 Validating sound prediction models, and 1.1.5 Obtaining source data for use in sound prediction models. 1.2 This guide may be used according to Guide E 1779 and specified in the measurement plan. 1.2.1 This guide can also be used to conduct measurements without a plan provided an operator/observer whose qualifications are satisfactory to both the performing organization and the user of the results is present at all times during the measurements and who complies with the applicable requirements of this guide, including record keeping. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== Situations for which outdoor sound level data are required include, but are not limited to, comparison of sound levels with criteria or regulatory limits. This guide provides information to ( 1 ) measure outdoor sound level in the vicinity of outdoor fixed noise sources, and ( 2 ) document other observations necessary for the measurements. This guide provides a standard procedure for a trained acoustical professional that will produce results and documentation which are consistent with the purposes cited in 1.1.1 - 1.1.5 . These sound measurements should be performed by or under the direction of a person experienced in the measurement and analysis of outdoor sound, and who is familiar with the use of the required equipment and techniques. This guide can be used by individuals, regulatory agencies, or others as a measurement guide to collect data on the sound level received from a fixed source within the constraints cited in 8.1 and Appendix X2 . This guide can be used to establish compliance or noncompliance at the time, distance, and conditions during which the data were obtained. However, this guide is only a measurement procedure and does not address the problem of projecting the acquired data outside those conditions, other times of day, other distances, or comparison with specific criteria. In particular, for a given sound source level, distant noise levels will often be found to be greater at night than during the day.