ASTM D7736-19a

5.1 The presence of acids or glycol esters in the glycol used to produce engine coolant is undesirable. Under conditions in an engine cooling system, the esters can hydrolyze to form glycol and an acid. The acid will react with the corrosion inhibitors, thereby reducing the useful life of the coolant. This method can determine the amount of acid and glycol ester present in the glycol.

1.1 This test method covers the determination of free acids and glycol esters in glycols by titration.

1.2 This test method is typically used on glycols used for the manufacture of engine coolant. It cannot be used on formulated engine coolant. The inhibitors will interfere with the determination.

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 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.

1.5 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.