ASTM D6660 for Freezing Point of Aqueous Ethylene Glycol Base Engine Coolants
ASTM D6660 Standard Test Method for Freezing Point of Aqueous Ethylene Glycol Base Engine Coolants by Automatic Phase Transition Method
4. Summary of Test Method
4.1 A specimen is cooled by a Peltier device while continuously being illuminated by a light source. The specimen is continuously monitored by an array of optical detectors for the first formation of crystals. Once the crystals are formed, the specimen is then warmed at controlled rates until all the crystals return to the liquid phase. The detectors are sufficient in number to ensure that any crystals are detected. The specimen temperature at which the crystals return to the liquid phase is recorded by the temperature sensor as the freezing point.
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.
5.3 Freezing point as measured by Test Method D1177 or approved alternative method is a requirement in Specifications D3306 and D6210.
5.4 This test method provides results that are equivalent to Test Method D1177 and expresses results to the nearest 0.1°C with improved reproducibility over Test Method D1177.
5.5 This test method determines the freezing point in a shorter period of time than Test Method D1177.
5.6 This test method removes most of the operator time and judgement required by Test Method D1177.
