1.1 本试验方法涵盖了导电基材上聚合物涂层的电化学阻抗谱（EIS）现场测量程序。 1.2 本试验方法涵盖了确定适当样本量的参数。 1.3 单位- 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。 1.4 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。 1.5 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====== 4.1 该测试方法适用于在用状态评估和质量控制（QC）测试。 4.2 该技术用于研究导电基材上的聚合物阻挡涂层，仅限于暴露和可接近的涂层表面。 4.3 本试验方法适用于所有厚度的聚合物阻隔涂层，前提是阻抗在设备能力范围内。评估超过2的涂层时需要特别考虑 毫米厚或含有导电介质，如金属颜料和导电聚合物。 4.4 该测试方法提供了确保正确应用现场EIS测试和报告其结果所需的实验方法。该测试方法每次测量使用两个测试电池，与基板没有电气连接 ( 1- 4. ) （与传统的三电极测量不同）以防止需要与底层结构进行电气连接。 注1: 双测试单元法测量两个单元下方的阻抗加上它们之间路径的阻抗。这种布置具有额外的误报/正报风险，而使用传统的三电极测量方法（其中与基板进行电气连接）不会遇到这种风险。对于本试验方法，假阳性定义为高于涂层典型阻抗值，假阴性定义为低于涂层典型阻抗值。在现场进行传统的三电极测量是可能的，但与基板的可靠电气连接可能具有挑战性，可能需要损坏其他良好的涂层。 4.5 该试验方法可在涂层系统寿命期间的任何时间使用。如果用于质量控制，则应考虑制造商建议的固化或干燥时间，除非参与方另有约定。 注2: 使用该测试方法获得的结果可用于知情的涂层维护决策，例如，是否更换涂层系统，也可用于涂层合同的QC测量。 4.6 使用本试验方法获得的结果不应被视为估算底层结构结构特性的手段。 4.7 使用该测试方法获得的结果并不能测量底层结构的腐蚀敏感性，因为它使用了两个与基板没有电连接的测试电池。根据，将开路电位和电压扰动应用于测试电池电极 5.3 ，而不是底层结构。 4.8 电化学阻抗测量应由在保护涂层和腐蚀测试领域有经验的工程师或技术专家进行解释。除电化学阻抗外，通常需要使用其他数据，如目视检查、干膜厚度和附着力测试，以得出有关底层结构腐蚀活性或涂层系统剩余使用寿命的结论。见测试方法 D660 , D661 , D714 ，或练习 D610 有关涂层目视检查的更多信息。

1.1 This test method covers the procedure for field measurement of electrochemical impedance spectroscopy (EIS) for polymeric coatings over conductive substrates. 1.2 This test method covers the parameters for determining an adequate sample size. 1.3 Units— The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 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. 1.5 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 ====== 4.1 This test method is suitable for in-service condition assessment and quality control (QC) testing. 4.2 This technique is used to investigate a polymer barrier coating over a conductive substrate and is limited to exposed and accessible coating surfaces. 4.3 This test method is applicable to polymer barrier coatings of all thicknesses provided the impedance is within equipment capabilities. Special considerations are required for evaluation of coatings exceeding 2 mm thickness or containing conductive media, such as metal pigments and conducting polymers. 4.4 This test method provides the experimental method needed to ensure proper application of field EIS testing and reporting of its results. This test method uses two test cells per measurement with no electrical connection to the substrate ( 1- 4 ) (a deviation from the traditional three-electrode measurement) to prevent the need for electrical connection to the underlying structure. Note 1: The two-test-cell method measures the impedances beneath the two cells plus the impedance of the path between them. This arrangement has additional risks of false negatives/positives that are not encountered using the traditional three-electrode measurement in which an electrical connection to the substrate is made. For this test method, a false positive is defined as a higher impedance value than is typical for the coating, and a false negative is defined as a lower impedance value than is typical for the coating. A traditional three-electrode measurement in the field is possible, but a reliable electrical connection to the substrate can be challenging and may require damage to an otherwise good coating. 4.5 This test method may be used at any time during the life of a coating system. If used for QC, allow for any manufacturer’s recommended cure or drying time unless otherwise agreed upon between the participating parties. Note 2: The results obtained by using this test method could be used for informed coating maintenance decisions, for example, whether to replace a coating system, and may also be applicable as QC measurement for coating contracts. 4.6 The results obtained by using this test method shall not be considered as a means for estimating the structural properties of the underlying structure. 4.7 The results obtained by using this test method do not measure the corrosion susceptibility of the underlying structure because it uses two test cells with no electrical connection to the substrate. The open circuit potential and voltage perturbation are applied to the test cell electrode, per 5.3 , and not the underlying structure. 4.8 The electrochemical impedance measurements shall be interpreted by engineers or technical specialists experienced in the fields of protective coatings and corrosion testing. It is often necessary to use other data such as visual inspection, dry film thickness, and adhesion testing, in addition to electrochemical impedance, to formulate conclusions concerning corrosion activity of the underlying structure or the remaining service life of the coating system. See Test Methods D660 , D661 , D714 , or Practice D610 for more information on coating visual inspection.