ASTM D1881 Test Method for Foaming Tendencies of Engine Coolants in Glassware
4. Summary of Test Method
4.1 A solution of coolant and ASTM Type II water is blown with air at a constant rate for 5 min, while maintained at a constant temperature of 88 +/- 1°C (190 +/- 2°F) by means of a suitable temperature bath. The volume of foam, and the time for such foam to break, are measured.
5. Significance and Use
5.1 The test method generally will distinguish coolants that have a tendency to foam excessively from those that are suitable for further evaluation to determine performance in actual service.
NOTE 1 - In use, the foaming tendency of a coolant solution may be increased by service aging or contamination. A properly functioning pressure cap will tend to suppress foaming in coolant solutions.
