1.1 本试验方法包括在规定的制备条件、速度、赫兹应力、材料、温度和大气条件下，通过螺旋轨道摩擦计（SOT）对标准试样进行试验时，油和润滑脂的摩擦系数和寿命的定量测定。本试验方法主要用于评估流体润滑剂在真空和环境条件下的使用寿命。 1.2 本标准可能涉及危险材料、操作和设备。本标准并不旨在解决与其使用相关的所有安全问题（如有）。 本标准的用户有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.3 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 螺旋轨道摩擦仪（SOT）的相关性- SOT旨在评估液体润滑剂在接触环境中的相对降解率，该环境类似于在边界润滑状态下运行的角接触轴承。它作为一种筛选装置，用于快速选择润滑剂，评估润滑剂的各种成分（基础油、增稠剂或添加剂）在滚动、旋转和滑动条件下同时润滑触点的能力，并在必要时研究其化学分解。SOT提供了一种方法来研究润滑油和润滑脂在运行期间的摩擦学行为，同时它们会随着润滑领域中遇到的典型参数（温度、环境、使用的材料、施加的载荷和速度）而发生变化。 试验结论定义为超过摩擦系数极限（通常高于稳态值0.1）时。归一化润滑剂寿命定义为完成的轨道数除以所用润滑剂的初始量（单位:μg）。SOT最初用于评估空间应用的润滑剂，但也适用于常规环境。给出了真空中的一些结果( 图1 ). 目前，尚未公布环境条件下的试验数据（见 图2 ). 本试验方法的使用者应自行确定本试验程序的结果是否与现场性能或其他台架试验程序相关。 图1 52100钢上三种典型空间润滑剂在23°C真空下的相对寿命 Pepper，S.V.，Kingsbury，E.P.，“螺旋轨道摩擦学——第二部分:真空中三种液体润滑剂的评估”， 摩擦学。Trans ., V 46，1，第65-69页，2003年 图2 440C钢在23°C下的全尺寸轴承试验**和SOT数据之间的比较。 Bazinet，D.G.，Espinosa，M.A.，Loewenthal，S.H.，Gschwender，L.，Jones，W.R.，Jr.，Predmore，R.E.，“使用四种空间液体润滑剂的扫描仪轴承的寿命”， Proc。37 th 航空航天机械。Symp。 , 约翰逊航天中心，2004年5月19日至21日

1.1 This test method covers the quantitative determination of the friction coefficient and the lifetime of oils and greases, when tested on a standard specimen under specified conditions of preparation, speed, Hertzian stress, materials, temperature, and atmosphere, by means of the Spiral Orbit Tribometer (SOT). This test method is intended primarily as an evaluation of the lifetimes of fluid lubricants under vacuum and ambient conditions. 1.2 This standard may involve hazardous materials, operations, and equipment. 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. 1.3 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 Relevance of the Spiral Orbit Tribometer (SOT)— The SOT was designed to evaluate the relative degradation rates of liquid lubricants in a contact environment similar to that in an angular contact bearing operating in the boundary lubrication regime. It functions as a screening device to quickly select the lubricants, evaluate the ability of various components of a lubricant (base oil, thickener, or additive) to lubricate a contact in rolling, pivoting, and sliding conditions simultaneously, and study their chemical decomposition if necessary. The SOT provides a means to study the tribological behavior of oils and greases during operation, while they undergo changes as a function of typical parameters encountered in the lubrication field (temperature, environment, materials used, load applied, and speed). Test conclusion is defined to be when a friction coefficient limit (typically an increase of 0.1 above the steady state value) is surpassed. Normalized lubricant lifetime is then defined as the number of orbits completed divided by the initial amount of lubricant used (in μg). The SOT was initially developed to evaluate lubricants for space applications, but is also relevant for conventional environments. Some results in vacuum are presented ( Fig. 1 ). At this time, no data for tests in ambient conditions have been published (see Fig. 2 ). The user of this test method should determine to their own satisfaction whether results of this test procedure correlate with field performance or other bench test procedures. FIG. 1 Relative lifetimes of three typical space lubricants at 23°C in vacuum on 52100 steel Pepper, S.V., Kingsbury, E.P., “Spiral Orbit Tribometry – Part II: Evaluation of Three Liquid Lubricants in Vacuum”, Tribo. Trans ., V 46, 1, pp 65-69, 2003 FIG. 2 Comparison between full scale bearing tests** and SOT data at 23°C on 440C steel. Bazinet, D.G., Espinosa, M.A., Loewenthal, S.H., Gschwender, L., Jones, W.R., Jr., Predmore, R.E., “Life of Scanner Bearings with Four Space Liquid Lubricants”, Proc. 37 th Aerospace Mech. Symp. , Johnson Space Center, May 19-21, 2004