1.1 本规程涵盖了一种进行定性声学探测的方法，即在可见剥离之前，用手持工具轻轻敲击新涂覆和先前安装的涂层/衬里系统，以评估与基底的潜在分离。规定了一个程序，以帮助确保各自探测方法的再现性。声音的解释是定性的，通常需要基本的训练，例如，使用敲击力的程度和听什么，这与正在评估的保护涂层或内衬系统的通用类型一致。 1.2 高性能涂层和衬里系统（与厚度无关）可以通过敲击试验进行测深评估，前提是避免敲击力过大，否则可能会对可接受的完好涂层造成冲击损坏。 1.3 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者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》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 涂层状况评估在很大程度上基于对涂层/衬里系统缺陷或损坏的目视观察。 视觉观察过程还可以识别缺陷（变色、开裂等）的前兆。此类目视检查可根据具体情况进行破坏性附着力测试。声学探测（轻敲测试）为破坏性测试提供了一种非破坏性的替代方法，以快速识别潜在涂层/衬膜脱落的区域，从而进行更具侵入性的检查，因为与基材的附着力差可能在视觉上不明显。 5.2 在正常的视觉观察过程中，可能会忽略敲击试验显示的可疑涂层或衬里附着力区域，直到故障的视觉指标（例如，起泡、裂纹、剥落或存在腐蚀）变得明显为止。 声学探测可以是一种预测性的通过/不通过检查，因为它提供了在剥离变得明显之前涂层/衬里系统和基底之间的结合减少的指示。 5.3 当评估浸没服务衬里的状况时，声学探测尤其有用，因为这些衬里可能覆盖着腐蚀产物、污渍或其他难以掩盖小缺陷的顽固沉积物( 注1 ). 由于高内聚强度，高性能涂层和衬里也可以在视觉上掩盖剥离和膜下腐蚀。 5.4 尽管使用声学探测（敲击）来确定潜在的涂层脱落相对简单，但所注意到的脱落程度取决于检查员对所产生声音的音调差异的解释。 同样，具有高水平的环境背景噪声的区域使得所产生的声音的音调差异难以区分。此外，数据记录必须使用草图和照片手动完成。 注1: 为了获得最佳效果，应在声学探测之前或结合声学探测对涂层或衬里进行清洁，因为有效使用敲击测试应包括同时进行目视检查。

1.1 This practice covers a method for conducting a qualitative acoustical sounding inspection by lightly tapping newly-applied and previously installed coating/lining systems with a hand-held tool to assess potential detachment from the substrate, prior to visible disbondment. A procedure is prescribed to help ensure reproducibility of the respective sounding methodology. Interpretation of the sound is qualitative and typically requires basic training, for example, the degree of tapping force to use and what to listen for, consistent with the generic type of protective coating or lining system being evaluated. 1.2 High performance coating and lining systems (independent of thickness) can be evaluated for sounding using the tap test, provided excessive tap force that may result in impact damage to otherwise acceptable, sound coatings is avoided. 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 Coating condition assessments are based, in large part, on visual observation of defects in or damage to the coating/ lining system. The visual observation process also identifies precursors of defects (discoloration, cracking, etc.). Such visual inspections may be augmented with destructive adhesion testing on a case-by-case basis. Acoustical sounding (tap testing) provides a non-destructive alternative to destructive testing to quickly identify areas of potential coating/lining film detachment for more intrusive examination, since poor adhesion to the substrate may not be visually evident. 5.2 Areas of suspect coating or lining adhesion revealed by the tap test may be overlooked during normal visual observation until visual indicators of failure (for example, blisters, cracks, peeling, or the presence of corrosion) become evident. Acoustical sounding can be a predictive go/no examination, in that it provides indication of a reduced bond between the coating/lining system and the substrate before disbonding becomes visually evident. 5.3 Acoustical sounding inspection is particularly useful when assessing the condition of immersion service linings that may be covered with corrosion product, staining, or other tenacious deposits that obscure small defects ( Note 1 ). High performance coatings and linings can also visually mask disbondment and under-film corrosion due to high cohesive strength. 5.4 Although the use of acoustical sounding (tapping) to determine potential coating detachment is relatively simple, the extent of the noted detachment is subject to the inspector’s interpretation of the tonal differences in the produced sound. Likewise, areas with high levels of ambient background noise make tonal differences of the produced sounds difficult to distinguish. Furthermore, data recording must be done manually using sketches and photographs. Note 1: For best results, the coating or lining should be cleaned prior to or in combination with acoustical sounding, as effective use of tap testing should include a concurrent visual examination.