1.1 本试验方法包括测量电泳槽及其超滤液中的游离氢离子浓度。 1.2 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。 1.3 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====== 4.1 pH值是样品游离氢离子浓度的测量值，它指示电泳槽是酸性、中性还是碱性。由于在水溶液中进行了高精度的pH测量，因此建议电泳槽的pH测量仅为半定量测量，因此此类测量应称为表观pH测量。 4.2 电泳涂料的pH值用于研究、生产和质量控制或电泳槽过程控制。 4.3 测试方法中描述了测定水或水系统pH值的其他相关方法 D1293号 和 E70 .

1.1 This test method covers the measurement of the free hydrogen ion concentration of electrocoat baths and their ultrafiltrates. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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 ====== 4.1 The pH is the measure of the free hydrogen ion concentration of a sample, and it indicates whether an electrocoat bath is acidic, neutral, or basic. Since pH measurements of good precision are made in aqueous solutions, it is suggested that the pH measurements of electrocoat baths are only semi-quantitative, and therefore such measurements should be referred to as apparent pH measurements. 4.2 The pH of electrocoat paints is used for research, production, and quality control or electrocoat bath process control. 4.3 Other related methods for determining the pH of water or aqueous systems are described in Test Methods D1293 and E70 .