ASTM D3519 Standard Test Method for Foam in Aqueous Media (Blender Test)
7. Procedure
7.1 Clean and rinse the blender with distilled water using 10 s blends and fresh samples of distilled water until no appreciable foam is developed by blending.
7.2 Place the blender jar in the constant-temperature bath. (The bath water should not be allowed inside the jar.)
7.3 Using the manufacturer's recommended procedure, prepare 200 ml of emulsion at the recommended use concentration.
7.4 When tap water is used, record water hardness (using Test Method D1126), source, and date obtained.
NOTE 3 - In the absence of manufacturers' recommendations, place 190 ml of distilled water in the 250-ml capacity glass-stoppered graduated cylinder. Pour a fine stream of coolant concentrate into the cylinder to bring the liquid level to the 200-ml mark, being careful not to run concentrate down the side of the cylinder. (A syringe or serological pipet with rubber bulb may be found convenient here.) Immediately, stopper and shake the cylinder to form a 5 % emulsion or solution.
7.5 Pour the test liquid into a clean glass bottle or jar and store it at 25 +/- 1°C (77 +/- 1.8°F) for a minimum of 1 h and a maximum of 2 h in the constant-temperature water bath deep enough so that the water level is at least 10 mm above the air-test fluid interface.
7.6 Assemble the blender.
7.7 Attach a millimetre rule to one side of the blender so that the 0 mm matches with the inside bottom of the blender jar.
NOTE 4 - Permanent attachment using epoxy cement may be found to be convenient. An adhesive-backed transparent measuring tape is also suitable.
7.8 Pour the test liquid into the blender jar.
7.9 Using any suitable thermometer, measure and record the temperature of this liquid and adjust it to 25 +/- 1°C (77 +/- 1.8°F) if necessary. Remove the thermometer and cover the blender jar.
7.10 Measure and record the test liquid height, disregarding any foam, to the nearest 1 mm. Call this the initial height, I.
7.11 Blend 30 +/- 1 s at between 4000 and 13000 rpm.
7.12 Shut off the blender and immediately measure the total height (including foam). This is called maximum total height at zero time. (If foam is not level, make the best average measurement possible.)
7.13 Allow the blender to stand undisturbed and record the time (to the nearest 1/2 min) for the foam to subside to a net foam height of 10 mm.
7.14 Record the total height to the nearest 1 mm as residual total height after 5 min if the foam height at this time exceeds 10 mm.
7.15 Measure and record the temperature of the test liquid to the nearest 1°C (1.8°F).
NOTE 5 - The following sections should be performed only when distilled water has been used in the above procedure in accordance with Note 3.
7.16 Add 1.0 ml of 20 000-ppm hard water stock solution to the emulsion. Blend on No. 1 or the lowest speed for 5 s to distribute the hard water stock uniformly. Allow the emulsion to sit quiet for 5 min; then proceed as in 7.17. (Warning - Differences in hydrolyzation time can yield differences in foaming properties.)
7.17 Repeat 7.9-7.15.
7.18 Rinse the blender as in 7.1.
NOTE 6 - 7.2 may be omitted prior to testing of other fluids in a single series of tests, provided a jar temperature approximating 25°C (77°F) is assured.
