1.1 本试验方法包括通过测量产生的伏安图中指定电压下的电流量，对浓度从0.0075%（重量）到新润滑脂中发现的浓度的新润滑脂或在用润滑脂中抗氧化剂进行伏安测定。 1.2 本试验方法旨在监测润滑脂中的抗氧化剂含量；它不能用于不含抗氧化剂的润滑脂。 1.3 该测试方法旨在使用户监测- 作为状态监测程序的一部分，在润滑脂的整个生命周期中使用润滑脂。执行此测试方法是为了收集润滑脂劣化的早期迹象并确定其趋势，它可作为指导任何所需维护活动的指南。这将确保受监控工厂设备的安全、可靠和经济高效的运行。 1.4 以国际单位制表示的数值应视为标准。本标准不包括其他计量单位。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如有）。 本标准的使用者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。 1.6 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====== 5.1 新润滑脂中抗氧化剂的定量测定测量添加到基础油中的化合物的量，以防止润滑脂氧化。对于在用润滑脂，伏安法测量润滑脂氧化降低其浓度后剩余的原始（单个）抗氧化剂的量。在对使用中的润滑脂的剩余使用寿命做出最终判断之前，建议执行其他分析技术，如试验方法 D942 和 D5483 ，其可用于测量所用润滑脂的剩余氧化寿命。 5.1.1 本试验方法适用于矿物油基和合成油基润滑脂，基于所有类型的增稠剂。本试验方法适用于至少含有一种抗氧化剂的润滑脂。其他类型添加剂（如缓蚀剂或金属钝化剂）的存在不会干扰本试验方法。 5.2 当使用中性丙酮测试溶液对用受阻酚和芳香胺抗氧化剂的典型协同混合物抑制的油脂进行伏安分析时，在8秒至12秒（或0。 施加电压为8 V至1.2 V），请参阅 注1 ，对于芳族胺，以及所产生的伏安图的伏安图电流在13秒至16秒之间（或1.3 V至1.6 V的施加电压）的增加，参见 注1 ，对于受阻酚。在里面 图1 ，x轴=1 s=0.1 V。通过伏安分析检测到的受阻酚抗氧化剂包括但不限于2,6-二- 叔 -丁基-4-甲基苯酚；2,6-二- 叔- 丁基苯酚和4,4'-亚甲基双（2,6-二- 叔 丁基苯酚）。通过伏安分析检测到的芳香胺抗氧化剂包括但不限于苯基α-萘胺和烷基化二苯胺。 5.3 对于仅含有芳香胺作为抗氧化剂的润滑脂，通过使用中性丙酮测试溶液（ 图1 ). 5.4 对于含有ZDDP作为抗氧化剂的润滑脂，应在6 s至10 s（或0.6 V至1.0 V的外加电压）之间增加伏安电流，见 注1 ，对于ZDDP，当在中性丙酮测试溶液中进行评估时。 5.5 对于仅含有受阻酚类抗氧化剂的润滑脂，建议按照试验方法中的说明使用碱性酒精试验溶液 D6810 在碱性酒精测试溶液中，苯酚的伏安图电流在3 s至6 s之间增加（或施加0.3 V至0.6 V的电压），见 注1 在里面 图2 ，x轴=1 s=0.1 V，如测试方法中所述 D6810 ，其中x轴=时间（秒），y轴是电流（任意单位）。顶部行在 图2 是新鲜油脂。

1.1 This test method covers the voltammetric determination of antioxidants in new or in-service lubricating greases in concentrations from 0.0075 % by weight up to concentrations found in new greases by measuring the amount of current flow at a specified voltage in the produced voltammogram. 1.2 This test method is intended to monitor the antioxidant content in lubricating greases; it cannot be applied for lubricating greases that do not contain antioxidants. 1.3 This test method is designed to allow the user to monitor the antioxidant depletion rate of in-service greases through its life cycle as part of condition monitoring programs. This test method is performed in order to collect and trend early signs of deteriorating lubricant grease, and it may be used as a guide for the direction of any required maintenance activities. This will ensure a safe, reliable, and cost-effective operation of the monitored plant equipment. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 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. 1.6 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 The quantitative determination of antioxidants in new greases measures the amount of the chemical compounds that were added to the base oil as protection against grease oxidation. For in-service oil greases, the voltammetric test method measures the amount of original (individual) antioxidants remaining after grease oxidation have reduced its concentration. Before making final judgment on the remaining useful life of the in-service grease, which might result in the replacement of the grease reservoir, it is advised to perform additional analytical techniques, such as Test Method D942 and D5483 , which may be used to measure the remaining oxidative life of the used grease. 5.1.1 This test method is applicable to mineral oil-based and synthetic oil-based greases, based on all type of applied thickeners. This test method is applicable to greases containing at least one type of antioxidant. The presence of other types of additives like corrosion inhibitors or metal deactivators will not interfere with this test method. 5.2 When a voltammetric analysis is obtained using a neutral acetone test solution for a grease inhibited with a typical synergistic mixture of hindered phenol and aromatic amine antioxidants, there is an increase in the voltammogram current between 8 s to 12 s (or 0.8 V to 1.2 V applied voltage), see Note 1 , for the aromatic amines, and an increase in the voltammogram current of the produced voltammogram between 13 s to 16 s (or 1.3 V to 1.6 V applied voltage), see Note 1 , for the hindered phenols. In Fig. 1 , x-axis = 1 s = 0.1 V. Hindered phenol antioxidants detected by voltammetric analysis include, but are not limited to, 2,6-di- tert -butyl-4-methylphenol; 2,6-di- tert- butylphenol and 4,4’-Methylenebis(2,6-di- tert butylphenol). Aromatic amine antioxidants detected by voltammetric analysis include, but are not limited to, phenyl alpha naphthylamines, and alkylated diphenylamines. 5.3 For greases containing only aromatic amines as antioxidants, there will only be an increase in the current of the produced voltammogram between 8 s to 12 s (or 0.8 V to 1.2 V applied voltage) for the aromatic amines, by using the neutral acetone test solution (first peak in Fig. 1 ). 5.4 For greases containing ZDDP as antioxidants, there shall be an increase in the voltammogram current between 6 s to 10 s (or 0.6 V to 1.0 V applied voltage), see Note 1 , for the ZDDP, when evaluated in the neutral acetone test solution. 5.5 For greases containing only hindered phenolic antioxidants, basic alcohol test solutions are recommended for use as described in Test Method D6810 . In basic alcohol test solutions, the voltammogram current for phenols increases between 3 s to 6 s (or 0.3 V to 0.6 V applied voltage), see Note 1 . In Fig. 2 , x-axis = 1 s = 0.1 V are as described in Test Method D6810 , where x-axis = time (seconds) and y-axis is current (arbitrary units). Top line in Fig. 2 is fresh grease.