ASTM D7669-20

5.1 This guide is intended to provide machinery maintenance and monitoring personnel with a guideline for performing trend analysis to aid in the interpretation of machinery condition data.

1.1 This guide covers practical techniques for condition data trend analysis.

1.2 The techniques may be utilized for all instrumentation that provides numerical test results. This guide is written specifically for data obtained from lubricant samples. Other data obtained and associated with the machine may also be used in determining the machine condition.

1.3 This guide provides a methodology for assessing changes in lubricant during service. For limits on a specific lubricant parameter used in different system types, users should refer to Practice D4378, Practice D6224, or other established industry criteria, such as from the OEM. Guide D7720 may be used to determine limits if unavailable through the other references given.

1.4 This guide does not address upper or lower control limits. These limits are provided by product manufacturers, defined in ASTM specifications, or both. The range between upper and lower control limits should be greater than the range within each test method’s repeatability coefficient. See Practices D3244, D6299, and D6792 for more information about ensuring that process control limits do not violate statistical fundamentals.

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.