1.1 本试验方法评估汽车柴油发动机使用中机油的耐通气性。它通常被称为Caterpillar-C13发动机机油充气测试（COAT）。测试在发动机高转速（1800 r/min），零负载条件下使用指定的Caterpillar 320 千瓦，直喷，涡轮增压，后冷却，六缸柴油发动机，专为重型公路卡车设计。本试验方法是作为试验方法的替代品而开发的 D6894 . 注1: 最新版本的规范中讨论了用于评估发动机机油性能以满足规范要求的配套测试方法 第4485天 . 1.2 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。 1.2.1 例外情况- 在没有直接SI等效物的情况下，例如螺纹、国家管道螺纹/直径和管道尺寸。 1.3 该试验方法安排如下: 部分 范围 1. 参考文件 2. 术语 3. 试验方法总结 4. 意义和用途 5. 仪器 6. 发动机液体和清洗溶剂 7. 仪器的准备 8. 发动机机座校准和非参考油测试 9 程序 10 计算、测试有效性和测试结果 11 汇报 12 精度和偏差 13 关键词 14 ASTM测试监控中心组织机构 附件A1 安全注意事项 附件A2 发动机和发动机制造零件套件 附件A3 油温控制系统 附件A4 发动机改装和仪表 附件A5 流量密度计校准或验证程序 附件A6 曝气测量系统 附件A7 指定的单位和格式 附件A8 ASTM TMC:校准程序 附件A9 ASTM TMC:维护活动 附件A10 ASTM TMC:相关信息 附件A11 发动机故障- in和硅钝化程序 附件A12 油样采集和分析时间表 附件A13 操作有效性的确定 附件A14 典型系统配置 附录X1 1.4 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。 看见 附件A2 一般安全预防措施。 1.5 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 背景- 在本试验方法之前，通过试验方法中所述的发动机油通气试验（EOAT）来测量发动机润滑剂抵抗通气的能力 D6894 发动机零件的持续可用性，加上现场服务的通风问题，导致人们担心这种测试方法与新的机油和发动机技术的相关性。这些问题促使开发了这种新的发动机机油充气测试方法，该方法基于Caterpillar C13发动机，称为COAT。该测试方法旨在为现场服务中发动机运行期间润滑剂抵抗充气的能力提供更可靠的测量。所使用的发动机是目前的技术，充气测量是独立于操作员的。 5.2 试验方法- 该测试方法评估高通气条件下的通气性能- 发动机转速，涡轮增压，重型，四冲程柴油发动机的零负荷运行。 5.3 使用: 5.3.1 在直喷涡轮增压柴油发动机中，机油充气的趋势受到多种因素的影响，包括机油配方、油温、油底壳设计和容量、油在油底壳中的停留时间以及加压油系统的设计。在一些发动机油激活系统中，机油在油底壳中的停留时间不足以使机油中的空气消散。因此，充气机油可能会循环到液压启动部件，从而对发动机正时特性和发动机运行产生不利影响。 5.3.2 此测试方法的结果可以与规范要求（如规范）进行比较 第4485天 以确定验收。 5.3.3 该试验方法中使用的试验发动机的设计代表了许多但不是所有的柴油发动机。 在将测试结果与规范要求进行比较时，需要考虑这一因素以及独特的操作条件。

1.1 This test method evaluates an engine oil's resistance to aeration in automotive diesel engine service. It is commonly referred to as the Caterpillar-C13 Engine-Oil Aeration Test (COAT). The test is conducted under high-engine-speed (1800 r/min), zero-load conditions using a specified Caterpillar 320 kW, direct-injection, turbocharged, after-cooled, six-cylinder diesel engine designed for heavy-duty, on-highway truck use. This test method was developed as a replacement for Test Method D6894 . Note 1: Companion test methods used to evaluate engine oil performance for specification requirements are discussed in the latest revision of Specification D4485 . 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.2.1 Exception— Where there is no direct SI equivalent, for example, screw threads, national pipe threads/diameters, and tubing size. 1.3 This test method is arranged as follows: Section Scope 1 Referenced Documents 2 Terminology 3 Summary of Test Method 4 Significance and Use 5 Apparatus 6 Engine Liquids and Cleaning Solvent 7 Preparation of Apparatus 8 Engine Stand Calibration and Non-Reference Oil Tests 9 Procedure 10 Calculation, Test Validity and Test Results 11 Report 12 Precision and Bias 13 Keywords 14 ASTM Test Monitoring Center Organization Annex A1 Safety Precautions Annex A2 Engine and Engine Build Parts Kit Annex A3 Oil Temperature Control System Annex A4 Engine Modifications and Instrumentation Annex A5 Flow Density Meter Calibration or Verification Procedure Annex A6 Aeration Measurement System Annex A7 Specified Units and Formats Annex A8 ASTM TMC: Calibration Procedures Annex A9 ASTM TMC: Maintenance Activities Annex A10 ASTM TMC: Related Information Annex A11 Engine Break-in and Silicon Passivation Procedure Annex A12 Schedule for Taking Oil Samples and Carrying out Analyses Annex A13 Determination of Operational Validity Annex A14 Typical System Configuration Appendix X1 1.4 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. See Annex A2 for general safety precautions. 1.5 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 Background— Prior to this test method, the ability of an engine lubricant to resist aeration was measured by the engine oil aeration test (EOAT) described in Test Method D6894 . The continued availability of engine parts coupled with field service aeration problems led to concerns about the relevance of this test method to newer oil and engine technologies. These concerns prompted the development of this new engine oil aeration test method, based on the Caterpillar C13 engine and termed COAT. This test method aims to provide a more reliable measurement of the ability of a lubricant to resist aeration during engine operation in field service. The engine used is of current technology and the aeration measurement is operator independent. 5.2 Test Method— This test method evaluates aeration performance under high-engine-speed, zero-load operation in a turbocharged, heavy-duty, four-stroke diesel engine. 5.3 Use: 5.3.1 The tendency of engine oils to aerate in direct-injection, turbocharged diesel engines is influenced by a variety of factors, including engine oil formulation, oil temperature, sump design and capacity, residence time of the oil in the sump, and the design of the pressurized oil systems. In some engine oil-activated systems, the residence time of the oil in the sump is insufficient to allow dissipation of aeration from the oil. As a consequence, aerated oil can be circulated to hydraulically activated components, adversely affecting the engine timing characteristics and engine operation. 5.3.2 The results from this test method may be compared against specification requirements such as Specification D4485 to ascertain acceptance. 5.3.3 The design of the test engine used in this test method is representative of many, but not all, diesel engines. This factor, along with the unique operating conditions, needs to be considered when comparing the test results against specification requirements.