1.1 本试验方法包括通过显微镜观察在涂膜中钻取的精密切割的浅角凹坑来测量涂膜的干膜厚度（DFT）。该坑显示了呈环状的横截面层，其宽度与涂层深度成正比，可以直接计算干膜厚度。 1.1.1 设备、程序、精度和偏差讨论包括方法A和方法B。方法A涉及使用光学测量设备。（这是“第一代”设备。）方法B是取代方法a的软件驱动的第二代测量程序。 1.2 基材可以是任何刚性金属材料，如冷轧钢、热浸镀锌钢、铝等。基材必须是平面的，但显示“线圈组”的基材除外，这些基材可以通过使用钻孔装置上的夹紧工具保持水平。 注1: 基材表面轮廓的变化可能会导致有机涂层厚度读数失真。这种情况可能存在于热浸镀锌钢板等基材上。这适用于用于确定有机涂层干膜厚度的所有“精密切割”方法。这就是为什么如果怀疑基材表面轮廓，在条带上进行多次测量可能是有用的。 1.3 厚度测量范围为0μm至89μm（0密耳至3.5密耳）。 注2: 对于大于89μm（3.5密耳）但小于1600μm（63密耳）的薄膜的DFT测量，根据本试验方法，可以使用45°钻孔器，但6.8除外，其中千分尺读数将提供直接读数，根据4.3.1方法a，不需要除以10。 1.4 可以在线圈上进行测量- 涂层板、某些成型产品或测试面板上。 1.5 以国际单位制表示的值应被视为标准。括号中给出的值仅供参考。 1.6 本标准并不旨在解决与其使用相关的所有安全问题（如果有的话）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.7 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====== 3.1 与非破坏性方法相比，通过物理切割薄膜并光学观察和测量厚度来测量有机涂层的干膜厚度具有直接测量的优点。 3.2 只要每层之间的附着力足够，通常可以通过这种测试方法单独测量组成涂层。然而，在底漆、面漆或多个涂层具有相同或非常相似的外观的情况下，这可能很困难。 A=0.1B

1.1 This test method covers the measurement of dry film thickness (DFT) of coating films by microscopic observation of a precision-cut, shallow-angle crater bored into the coating film. This crater reveals cross sectional layers appearing as rings, whose width is proportional to the depth of the coating layer(s) and allows for direct calculation of dry film thickness. 1.1.1 The Apparatus, Procedure, and Precision and Bias discussions include Method A and Method B. Method A involves the use of an optical measurement apparatus. (This is a “first-generation” device.) Method B is a software driven second-generation measurement procedure that supersedes Method A. 1.2 The substrate may be any rigid, metallic material, such as cold-rolled steel, hot-dipped galvanized steel, aluminum, etc. The substrate must be planar with the exception of substrates exhibiting “coil set,” which may be held level by the use of the clamping tool on the drilling device. Note 1: Variations in the surface profile of the substrate may result in misrepresentative organic coating thickness readings. This condition may exist over substrates such as hot-dipped, coated steel sheet. This is true of all “precision cut” methods that are used to determine dry film thickness of organic coatings. This is why several measurements across the strip may be useful if substrate surface profile is suspect. 1.3 The range of thickness measurement is 0 μm to 89 μm (0 mils to 3.5 mils). Note 2: For DFT measurements of films greater than 89 μm  (3.5 mils), but less than 1600 μm (63 mils), a 45° borer may be used in accordance with this test method, with the exception of 6.8, where the micrometer reading would provide a direct read-out, and division by ten would be unnecessary per 4.3.1 Method A. 1.4 Measurements may be made on coil-coated sheet, certain formed products, or on test panels. 1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.6 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. 1.7 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 ====== 3.1 Measurement of dry film thickness of organic coatings by physically cutting through the film and optically observing and measuring the thickness offers the advantage of direct measurement as compared with nondestructive means. 3.2 Constituent coating layers can usually be measured individually by this test method, provided adhesion between each layer is sufficient. However, this can be difficult in cases where the primer, topcoat, or multiple coating layers have the same, or very similar, appearance. A = 0.1B