1.1 本指南通过识别明确描述声学性能所需的信息，涵盖了各种隔音罩声学性能标准的制定。本指南不是隔声罩的标准ASTM规范。 1.2 本指南的范围不包括与声学性能不直接相关的外壳设计的技术考虑因素。 1.3 本标准并非旨在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、健康和环境实践，并确定监管限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 本指南可用于制定外壳声学性能规范。 5.2 本指南适用于熟悉声学基本概念的人。 5.3 尽管本指南提供了与隔声罩规范相关事项的详细指南，但它不能替代声学或噪声控制专业人员的经验和判断。 5.3.1 本指南要求声学实践中常见的测量。 5.3.2 外壳的性能要求越关键，用户就越应该考虑寻求声学或噪声控制专业人员的服务。 5.4 隔声罩的指定有三个连续步骤: 5.4.1 在引入外壳之前，确定特定位置存在的声压级， 注1: 对于新建筑，声压级通常根据噪声发射设备的声功率级和环境声学特性的一般描述进行估计。 5.4.2 确定引入外壳后相同位置必须存在的最大允许声压级，以及 5.4.3 确定所需的机柜液位降低。所需的隔离与引入外壳前后的声压级差有关。 5.5 许多规范适用于多个机柜或具有多个功能的机柜，或两者兼有。为每种可能的组合提供详细指导超出了本指南的范围。在这种情况下，应使用每个源-外壳-接收器组合的单独规范。 5.6 应选择的规格类型取决于外壳的用途及其性能的重要性。一般来说: 5.6.1 如果超过特定的最大允许声压级频谱将导致外壳不成功，则应使用声压级规范。 5.6.1.1 本指南将声学设计的所有阶段委托给供应商。合规性通常比电平降低法更容易验证。 5.6.2 如果外壳成功的标准不太严格或与特定的最大允许频谱无关，则可以使用电平降低规范。

1.1 The guide covers the development of criteria for the acoustical performance of a broad variety of acoustical enclosures by identifying information necessary to unambiguously describe acoustical performance. This guide is not a standard ASTM specification for a sound-isolating enclosure. 1.2 Excluded from the scope of this guide are technical considerations for enclosure design that do not pertain directly to acoustical performance. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This guide can be used to produce a specification for the acoustical performance of an enclosure. 5.2 This guide is intended for those familiar with basic concepts of acoustics. 5.3 Although this guide provides detailed guidance in matters relating to specification of acoustical enclosures, it is not a substitute for the experience and judgment of an acoustical or noise control professional. 5.3.1 This guide calls for measurements common within acoustical practice. 5.3.2 The more critical the performance requirements of the enclosure, the more the user should consider seeking the services of an acoustics or noise control professional. 5.4 The specifying of a sound-isolating enclosure has three sequential steps: 5.4.1 Determine the sound pressure levels that exist at specific locations prior to the introduction of the enclosure, Note 1: In the case of new construction, the sound pressure level is often estimated from the sound power levels of noise-emitting equipment and a general description of the acoustical properties of the environment. 5.4.2 Determine the maximum permissible sound pressure levels that must exist at the same locations after the introduction of the enclosure, and 5.4.3 Determine the required enclosure level reduction. The required isolation is related to the difference between the sound pressure levels before and after the introduction of the enclosure. 5.5 Many specifications are for multiple enclosures or enclosures with multiple functions, or both. It is beyond the scope of this guide to provide detailed guidance for every possible combination. Separate specifications for each source-enclosure-receiver combination should be used in such a case. 5.6 The type of specification that should be selected depends both on the purpose of the enclosure and how crucial its performance is. In general: 5.6.1 If exceeding a particular maximum permissible sound pressure level spectrum would render the enclosure unsuccessful, a sound pressure level specification should be used. 5.6.1.1 This guide assigns all phases of acoustical design are delegated to the supplier. Compliance is usually more easily verified than with the level reduction method. 5.6.2 If the criteria for the success of the enclosure are less stringent or not related to a specific maximum permissible spectrum, a level reduction specification may be used.