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ASTM D 7946 : 2019

Current
Current

The latest, up-to-date edition.

Standard Test Method for Initial pH (i-pH)-Value of Petroleum Products
Available format(s)

Hardcopy , PDF

Language(s)

English

Published date

01-01-2020

1.1This test method covers procedures for the determination of initial pH (i-pH) in new and in-service lubricants.

Note 1:In new and used oils, the constituents that may be considered to have characteristics influencing the i-pH value include organic and inorganic acids, esters, phenolic compounds, lactones, resins, salts of heavy metals, salts of ammonia and other weak bases, acid salts of polybasic acids, and addition agents such as inhibitors and detergents. “Initial” is used to differentiate from aqueous systems. The analysis is terminated after a defined time interval whenever equilibrium conditions, as known for pH measurements in aqueous systems, are not reached (see 3.1.1.2)

1.2This test method is used to indicate relative changes that occur in oil during use under oxidizing conditions or due to contamination by blow-by gases of combustion processes of biogases regardless of the color or other properties of the in-service lubricants. Although the initial pH is made under definite equilibrium conditions, the test method is not intended to measure an absolute acidic property that can be used to predict performance of oil under service conditions. No general correlation between corrosion of non-ferrous bearing metals and initial pH value is known.

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

1.4This 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.

1.5This 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.

Committee
D 02
DocumentType
Test Method
Pages
5
PublisherName
American Society for Testing and Materials
Status
Current
Supersedes

ASTM D 4057 : 2019 Standard Practice for Manual Sampling of Petroleum and Petroleum Products
ASTM D 4177 : 2022 Standard Practice for Automatic Sampling of Petroleum and Petroleum Products
ASTM D 4057 : 2022 Standard Practice for Manual Sampling of Petroleum and Petroleum Products
ASTM D 4177 : 2020 Standard Practice for Automatic Sampling of Petroleum and Petroleum Products
ASTM D 4177 : 2022 : EDT 1 Standard Practice for Automatic Sampling of Petroleum and Petroleum Products

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