Rust-preventing characteristics of inhibited mineral oil in the presence of water
5. Apparatus
5.1 Oil Bath - A thermostatically controlled liquid bath capable of maintaining the test sample at a temperature of 60 more or less 1°C (140 more or less 2°F) (see Note 4). An oil having a viscosity of approximately ISO VG 32 (see Classification D 2422) is suitable for the bath. The bath shall have a cover with holes to accommodate the test beakers.

NOTE 4 - ASTM Thermometer 9C (9F), as prescribed in Specification E 1, or IP Thermometer 21C in accordance with IP Standard Thermometers, Volume 2, Appendix A, is suitable to indicate the temperature. Alternatively, calibrated thermocouples may be used.

5.2 Beaker - A 400-mL, Berzelius-type, tall-form heat-resistant glass beaker without pourout, as shown in Fig. 1, approximately 127 mm (5 in.) in height measured from the inside bottom center and approximately 70 mm (2 3/4 in.) in inside diameter measured at the middle.

5.3 Beaker Cover - A flat beaker cover of glass or poly (methyl methacrylate) (PMMA) (Note 5), kept in position by suitable means such as a rim or groove. Two holes shall be provided on any diameter of the cover; one for a stirrer 12 mm (15/32 in.) in diameter with its center 6.4 mm (1/4 in.) from the center of the cover; and the other, on the opposite side of the center of the cover, for the test rod assembly (see Section 8), 18mm (45/64 in.) in diameter with its center 16 mm (5/8 in.) from the center of the cover. In addition, a third hole 12 mm (15/32 in.) in diameter shall be provided for a temperature measuring device, with its center 22.5 mm (7/8 in.) from the center of the cover and on a diameter of the cover at right angles to the diameter through the other two holes.

NOTE 5 - An inverted petri dish makes a suitable cover, as the sides of the dish aid in keeping it in position. Fig. 2 shows a PMMA resin cover for the beaker which has been found to be suitable. An optional feature is shown, consisting of a slot, 1.6 by 27 mm (1/16 by 1 1/16 in.), which is centered on a diameter of the stirrer hole at right angles to the cover diameter through the test rod hole and stirrer hole. This feature allows withdrawal of the stirrer while the beaker cover is in place. When the test method test is used for other fluids such as synthetics, the beaker cover should be made from chemically resistant material such as polymonochlorotrifluoroethylene (PCTFE).

5.4 The plastic holder shall be made of PMMA resin in accordance with the dimensions shown in Fig. 3 (two types of holders are illustrated). When testing synthetic fluids, the plastic holder should be made from chemically resistant material such as polytetrafluoroethylene (PTFE).

5.5 Stirrer - A stirrer constructed entirely from stainless steel (Note 6 and Note 7) in the form of an inverted T. A flat blade 25 by 6 by 0.6 mm (1 by 0.24 by 0.024 in.) shall be attached to a 6-mm (0.24-in.) rod in such a way that the blade is symmetrical with the rod and has its flat surface in the vertical plane.

NOTE 6 - A suitable material is an 18 % chromium, 8 % nickel alloy steel conforming to Type 304, of Specification A 240/A 240M, or SAE No. 30304 (see SAE J405), or BS 970: Part 1: 1983: 302S31.

NOTE 7 - If stainless steel is not obtainable, stirrers made of heat-resistant glass and having approximately the same dimensions as the stainless steel stirrers specified can be used.

5.6 Stirring Apparatus - Any convenient form of stirring apparatus capable of maintaining a speed of 1000 more or less 50 rpm.

5.7 Grinding and Polishing Equipment - A CAMI 150-grit (99-µm) and a CAMI 240-grit (53.5-µm) in accordance with BS 871 or its equivalent, metalworking aluminum oxide abrasive cloth coat on a jeans backing (the corresponding European grades (FEPA) are P150J and P280J, respectively), a suitable chuck (see Fig. 4) for holding the test rod, and a means of rotating the test rod at a speed of 1700 to 1800 rpm.

NOTE 8 - CAMI (Coated Abrasives Manufacturers Institute) is a United States organization and FEPA (Federation of European Producers of Abrasives) is a European organization.

5.8 Oven, capable of maintaining a temperature of 65°C (150°F).