1.1 本试验方法描述了使用超声波薄膜测厚仪准确、无损地测量涂覆在不同材料基材上的有机涂层的干膜厚度。可以在现场结构、商业制造的产品或实验室试样上进行测量。这些类型的测量仪可以准确测量各种基材上有机涂层的干膜厚度，如混凝土、木材、墙板、塑料、纤维复合材料和金属。 1.2 本试验方法不适用于在测量仪器负载下容易变形的涂层，因为仪器探头直接放置在涂层表面上进行读数。 1.3 使用超声波原理的仪器的有效范围受到量规设计的限制。已证明厚度范围为8μm至7.60 mm（0.3至300密耳）。 1.4 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.5 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。 1.6 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 干膜的膜厚显著影响许多涂层性能，如附着力、柔韧性、磨损、耐久性、耐化学性和硬度。为了能够比较不同操作员获得的结果，必须仔细测量膜厚度。 5.2 大多数保护性和高性能涂层的应用都是为了满足每层涂层干膜厚度的要求或规范，或整个系统的要求或规范，或两者兼而有之。涂层必须在一定的最小和最大厚度公差范围内涂覆，以实现其预期功能。除了潜在的性能缺陷外，在涂覆大面积（如地板和墙壁）时，使用超过必要数量的材料是不经济的。 5.3 表面粗糙的涂层上偶尔会出现低读数。 仪器可能允许用户调整以防止出现这种情况。 5.4 本试验方法可能不适用于测量所有基材上的有机涂层厚度。如果涂层和基材的成分、密度或衰减相似，或者涂层不均匀，则仪器检测涂层和基材之间不同界面的能力可能会受到阻碍。如果认为存在这些情况，则验证在已知厚度的涂层/基材组合上的操作。 5.5 多层涂层有许多界面，仪器将测量到分离两种声学差异最大的材料的界面。 一些仪器能够检测和测量多层系统中的单个层厚度。 5.6 本试验方法的使用不一定受到基材类型的限制。

1.1 This test method describes the use of ultrasonic film thickness gages to measure accurately and nondestructively the dry film thickness of organic coatings applied over a substrate of dissimilar material. Measurements may be made on field structures, on commercially manufactured products, or on laboratory test specimens. These types of gages can accurately measure the dry film thickness of organic coatings on a variety of substrates such as concrete, wood, wallboard, plastic, fiber composites and metal. 1.2 This test method is not applicable to coatings that will be readily deformable under load of the measuring instrument as the instrument probe is placed directly on the coating surface to take a reading. 1.3 The effective range of instruments using the principle of ultrasonics is limited by gage design. A thickness range of 8 μm to 7.60 mm (0.3 to 300 mils) has been demonstrated. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 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. 1.6 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 Many coating properties are markedly affected by the film thickness of the dry film such as adhesion, flexibility, wear, durability, chemical resistance, and hardness. To be able to compare results obtained by different operators, it is essential to measure film thickness carefully. 5.2 Most protective and high performance coatings are applied to meet a requirement or a specification for the dry-film thickness of each coat, or for the complete system, or both. Coatings must be applied within certain minimum and maximum thickness tolerances in order that they can fulfill their intended function. In addition to potential performance deficiencies, it is uneconomical to apply more material than necessary when coating large areas such as floors and walls. 5.3 Low readings may occur occasionally on coatings with rough surfaces. The instrument may allow a user adjustment to prevent this. 5.4 This test method may not be applicable to measure organic coating thickness on all substrates. The instrument's ability to detect a distinct interface between the coating and the substrate may be impeded if the coating and the substrate are of similar composition, density or attenuation or if the coating is non-homogeneous. Verify operation on a known thickness of the coating/substrate combination if these circumstances are thought to exist. 5.5 Multilayered coatings have many interfaces and the instrument will measure to the interface separating the two most acoustically different materials. Some instruments have the ability to detect and measure the individual layer thicknesses in a multi-layer system. 5.6 The use of this test method is not necessarily limited by the type of substrate material.