ASTM D1177 Test Method for Freezing Point of Aqueous Engine Coolants
4. Summary of Test Method
4.1 This test method involves the determination of the time-temperature curve prior to freezing and the determination of the horizontal or flattened portion of the freezing curve. The freezing point is taken as the intersection of projections of the cooling curve and the freezing curve. If the solution super-cools, the freezing point is the maximum temperature reached after supercooling.
5. Significance and Use
5.1 The freezing point of an engine coolant indicates the coolant freeze protection.
5.2 The freezing point of an engine coolant may be used to determine the approximate glycol content, provided the glycol type is known.
