5.1 The tendency of oils to foam at high temperature can be a serious problem in systems such as high-speed gearing, high volume pumping, and splash lubrication. Foaming can cause inadequate lubrication, cavitation, and loss of lubricant due to overflow, and these events can lead to mechanical failure.

5.2 Correlation between the amount of foam created or the time for foam to collapse, or both, and actual lubrication failure has not been established. Such relations should be empirically determined for foam sensitive applications.

1.1 This test method describes the procedure for determining the foaming characteristics of lubricating oils (specifically transmission fluid and motor oil) at 150 °C.

1.2 Foaming characteristics of lubricating oils at temperatures up to 93.5 °C are determined by Test Method D892 or IP 146.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 WARNING—Mercury has been designated by many regulatory agencies as a hazardous material that can cause central nervous system, kidney and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury containing products. See the applicable product Material Safety Data Sheet (MSDS) for details and EPA’s website—http://www.epa.gov/mercury/faq.htm—for additional information. Users should be aware that selling mercury and/or mercury containing products into your state or country may be prohibited by law.

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 and health 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.