ASTM D6794 Standard Test Method for Measuring the Effect on Filterability of Engine Oils After Treatment with Various Amounts of Water and a Long (6-h) Heating Time
6. Apparatus
6.1 The apparatus consists of a 25-mL burette, a filter holder with 25-µm automotive oil filter paper, and a source of 69 +/- 2 kPa (10 +/- 0.3 psi) air pressure. Discs of filter paper are cut to fit the holder and installed (see Fig. 1).
6.1.1 Burette (glass or plastic), 25 mL, with polytetrafluoroethylene (PTFE) stopcock and 1.8 +/- 0.1-mm burette tip opening.
6.1.2 Air Regulator, capable of regulating air to a pressure of 69 +/- 2 kPa (10 +/- 0.3 psi).
6.1.3 Filter Holder, with effective filter area approximately 0.8 cm2.
6.1.4 Automotive Oil Filter Paper, 25 mm, (25-µm porosity).
6.2 Blender, capable of 18 000 r/min +/- 10 % without the container.
6.2.1 Timer, capable of timing 30 +/- 1 s.
6.3 Container with Blade, 250 mL, compatible with the blender.
6.4 Syringe, 1000 µL.
6.5 Glass Jars, 60 mL, with inert lined lids.
6.6 Mechanical Convection Oven, capable of maintaining 70 +/- 1°C.
6.7 Sensors (or equivalent timing devices), capable of measuring sequential events to 1 s resolution.
7. Reagents
7.1 Purity of Reagents - Use reagent grade chemicals in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.
7.2 Purity of Water - Unless otherwise indicated, references to water shall be understood to mean Test Method D1193 Type III deionized water or water of equivalent purity.
7.3 TMC Reference Oils - These are available from the Test Monitoring Center.
8. Sampling
8.1 Take samples in accordance with the instructions in Practice D4057.
9. Preparation of Test Oil Sample and Filter
9.1 Mix 49.7 +/- 0.1 g of test oil, 0.3 +/- 0.05 g (0.3 +/- 0.05 mL with the 1000-µLsyringe) of deionized water in the blender for 30 +/- 1 s at 18 000 r/min +/- 10 %. Cover the top of the container loosely to prevent oil spattering.
9.2 Transfer the sample to a 60-mL wide mouth glass bottle and place the loosely capped (1/4 turn) bottle in an oven at 70.0 +/- 1.0°C for 6 h. Remove from the oven, tighten cap, and allow to cool to room temperature (20 to 24°C).
9.3 Repeat 9.1 and 9.2 with 0.5 g water, 1.0 g water, and 1.5 g water.
9.4 Store in dark at room temperature (20 to 24°C).
9.5 Determine filterability 48 +/- 2 h after removing the sample from the oven.
9.6 Dry filters in an oven at 70 +/- 2°C for 30 +/- 2 min and store in a desiccator until used.
