1.1 本试验方法包括测定由植物鞣制材料制成的制革液的酸度。 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====== 5.1 本试验方法用于测定与植物鞣制过程有关并影响植物鞣制液收敛性的鞣制液的化学性质之一。 白酒的涩味取决于固体、单宁含量和酸度。本试验方法提供了测定植物鞣液样品总酸度的标准程序。 5.2 样品是从为此目的收集的制革液样品中制备的分析溶液的等分试样。 5.3 通过本试验方法中描述的两种滴定程序之一测定白酒样品的总酸度。

1.1 This test method covers determining the acidity of tannery liquors made up from vegetable tanning materials. 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 ====== 5.1 This test method is used to determine one of the chemical properties of tannery liquors which are relevant for the vegetable tanning process and influence the astringency of vegetable tanning liquors. The astringency of liquors is dependent upon the solids and tannin content and the acidity. This test method provides a standard procedure for determining the total acidity for any sample of vegetable tanning liquor. 5.2 The specimens are aliquots from the analytical solution prepared from the sample of tannery liquor collected for this purpose. 5.3 The total acidity of the liquor sample is determined by one of two titrametric procedures described in this test method.