ASTM D8126-21 - Standard Test Method for Efficient Basicity Determination by Potentiometric Hydrochloric Acid Titration

1.1 This test method covers a procedure for the determination of the efficient basicity (EBas) in new marine cylinder lubricants that lubricate the upper part, that is, piston-ring-cylinder area, of two-stroke marine engines.

1.2 This test method has been developed for marine cylinder lubricants, having base number (BN) (measured by Test Method D2896) from 20 mg KOH/g to 100 mg KOH/g, and an EBas from 10 mg KOH/g to 36 mg KOH/g.

1.3 In this test method, only the efficient basicity is determined, corresponding to the components or part of components that have a major role in neutralization of the acidic species formed in the combustion of the fuel in the marine engine. It differentiates between the fastest reacting species and the last one to react like overbasing compounds in detergent (classically mineral calcium carbonate, CaCO₃). The values obtained, however, are intended to be compared with the other values obtained by this test method only; base numbers obtained by this test method are not intended to be equal to values by other test methods.

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

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. Some specific hazards statements are given in Sections 6 and 7.

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.