1.1 本试验方法涵盖了由植物鞣制材料制成的制革液的分析。 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制革液的化学性质。 白酒的涩味取决于固体、单宁含量和酸度。该方法为测定任何植物鞣液样品的这些特性提供了标准程序。 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 测定总固形物、可溶性固形物和非单宁含量，然后计算酒样的单宁含量。 因为每升分析溶液中的单宁含量低于试验方法所需的含量 D6401 ，本试验方法中包含一个表，规定了用于较低单宁浓度溶液的制备皮粉的数量。 5.4 白酒样品的总酸度通过试验方法中描述的两种滴定程序之一测定 D6410 . 5.5 该测试方法的结果取决于许多变量，但尤其取决于: 溶液制备和储存的温度条件以及进行电流分析的温度；沉积在滤纸上的高岭土膏层的均匀性和稠度；溶液从移液管流出的速率；与用于与溶液中单宁含量反应的皮粉性质有关的条件；因此，必须严格遵循该方法，以便在实验室内的样本之间和实验室之间的分析中获得可重复的结果。

1.1 This test method covers the analysis 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 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 method provides a standard procedure for determining these properties 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 solids, soluble solids, and non-tannins content are determined and then the tannin content of the liquor sample is calculated. Because the amount of tannin per liter of analytical solution is less than that required for Test Method D6401 , a table specifying the quantity of prepared hide powder to be used for solutions with lower tannin concentrations is included in this test method. 5.4 The total acidity of the liquor sample is determined by one of two titrametric procedures described in Test Method D6410 . 5.5 The results of this test method are dependent on a great many variables but particularly upon: the temperature conditions under which the solutions were prepared and stored and the temperature at which the current analysis is performed; the uniformity and consistency of the Kaolin paste layer deposited onto the filter paper; the rate of solution run-out from the pipette; conditions related to the properties of the hide powder used to react with the tannin content of the solution; etc. It is, therefore, essential that the method be followed exactly in order to obtain reproducible results both among specimens within a laboratory and for analyses between laboratories.