1.1 本试验方法包括监测在用石油和碳氢化合物润滑剂中的氧化情况，如柴油曲轴箱、电机、液压、齿轮和压缩机油，以及其他类型的易氧化润滑剂。 1.2 本试验方法使用傅里叶变换红外（FT-IR）光谱法监测正常机械操作导致的在用石油和碳氢化合物润滑剂中氧化产物的积累。石油和碳氢化合物润滑剂与空气中的氧气反应，形成许多不同的化学物质，包括醛类、酮类、酯类和羧酸。本试验方法设计为一种快速、简单的光谱检查，用于监测在用石油和碳氢化合物润滑剂中的氧化情况，目的是通过测量油中的氧化程度来帮助诊断机器的操作条件。 1.3 实践中描述了用于测量在用机油和润滑剂样品中氧化的FT-IR光谱数据的采集 D7418号 在该测试方法中，给出了使用直接趋势分析和差分（光谱减法）趋势分析的氧化测量和数据解释参数。 1.4 本试验方法基于与在用石油和碳氢化合物润滑剂氧化相关的光谱变化趋势。警告或警报限值可以根据单个测量的固定最小值设置，或者也可以根据测量的响应变化率设置，参见参考 ( 1. ) . 2. 1.4.1 对于直接趋势分析，直接从吸收光谱记录数值，并以每0.1吸光度单位报告 mm路径长度。 1.4.2 对于差异趋势分析，从差异光谱中记录数值（通过将参考油的吸收光谱从中减去而获得的光谱- 服务油），并以每0.1倍100*吸光度为单位报告 mm路径长度（或每厘米等效吸光度单位）。 1.4.3 在任何一种情况下，应通过统计分析、相同或类似设备的历史记录、循环试验或其他方法，结合氧化变化与设备性能的相关性，确定维护行动限值。 注1: 本试验方法的目的不是为任何机械确定或建议正常、警告、警告或警戒限值。应结合机械制造商和维护小组的建议和指导，确定此类限制。 1.5 本试验方法适用于石油和碳氢化合物润滑油，不适用于酯基润滑油，包括多元醇酯或磷酸酯。 1.6 以国际单位表示的数值视为标准值。 本标准不包括其他计量单位。 1.6.1 例外情况- 波数单位为厘米 –1 . 1.7 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。 1.8 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 当油与大气中的氧气反应时，会产生大量的化合物，如醛类、酮类、酯类和羧酸。 使用1800之间的常见FT-IR光谱特征测量氧化 厘米 –1 和1670 厘米 –1 由大多数氧化化合物中存在的羰基吸收引起。这些氧化产物可能会导致粘度增加（导致油稠化问题）、酸度增加（导致酸性腐蚀），并形成污泥和清漆（导致过滤器堵塞、关键油隙污染和阀门摩擦）。因此，氧化产物的监测是确定整体机械健康状况的一个重要参数，应结合原子发射（AE）和用于磨损金属分析的原子吸收（AA）光谱等其他试验的数据来考虑（试验方法 D5185型 )和物理性能试验（试验方法 D445号 )，基础储备（试验方法 D2896型 和 D4739号 )酸值试验（试验方法 D664型 和 D974号 )和其他FT- 硝化的红外油分析方法（试验方法 D7624号 )，硫酸盐副产品（试验方法 D7415号 )和添加剂消耗（试验方法 D7412号 )，它还评估了石油状况的要素，参见参考文献 ( 1- 6. ) .

1.1 This test method covers monitoring oxidation in in-service petroleum and hydrocarbon based lubricants such as in diesel crankcase, motor, hydraulic, gear and compressor oils, as well as other types of lubricants that are prone to oxidation. 1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring build-up of oxidation products in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Petroleum and hydrocarbon based lubricants react with oxygen in the air to form a number of different chemical species, including aldehydes, ketones, esters, and carboxylic acids. This test method is designed as a fast, simple spectroscopic check for monitoring of oxidation in in-service petroleum and hydrocarbon based lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of oxidation in the oil. 1.3 Acquisition of FT-IR spectral data for measuring oxidation in in-service oil and lubricant samples is described in Practice D7418 . In this test method, measurement and data interpretation parameters for oxidation using both direct trend analysis and differential (spectral subtraction) trend analysis are presented. 1.4 This test method is based on trending of spectral changes associated with oxidation of in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref ( 1 ) . 2 1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength. 1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption spectrum of the reference oil from that of the in-service oil) and reported in units of 100*absorbance per 0.1 mm pathlength (or equivalently absorbance units per centimetre). 1.4.3 In either case, maintenance action limits should be determined through statistical analysis, history of the same or similar equipment, round robin tests, or other methods in conjunction with the correlation of oxidation changes to equipment performance. Note 1: It is not the intent of this test method to establish or recommend normal, cautionary, warning, or alert limits for any machinery. Such limits should be established in conjunction with advice and guidance from the machinery manufacturer and maintenance group. 1.5 This test method is for petroleum and hydrocarbon based lubricants and is not applicable for ester based oils, including polyol esters or phosphate esters. 1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6.1 Exception— The unit for wave numbers is cm –1 . 1.7 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. 1.8 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 A large number of compounds, such as aldehydes, ketones, esters, and carboxylic acids, are produced when oils react with atmospheric oxygen. Oxidation is measured using a common FT-IR spectral feature between 1800 cm –1 and 1670 cm –1 caused by the absorption of the carbonyl group present in most oxidation compounds. These oxidation products may lead to increased viscosity (causing oil thickening problems), acidity (causing acidic corrosion), and formation of sludge and varnish (leading to filter plugging, fouling of critical oil clearances and valve friction). Monitoring of oxidation products is therefore an important parameter in determining overall machinery health and should be considered in conjunction with data from other tests such as atomic emission (AE) and atomic absorption (AA) spectroscopy for wear metal analysis (Test Method D5185 ) and physical property tests (Test Methods D445 ), base reserve (Test Method D2896 and D4739 ), acid number tests (Test Methods D664 and D974 ) and other FT-IR oil analysis methods for nitration (Test Method D7624 ), sulfate by-products (Test Method D7415 ), and additive depletion (Test Method D7412 ), which also assess elements of the oil’s condition, see Refs ( 1- 6 ) .