ASTM D4742 Test Method for Oxidation Stability of Gasoline Automotive Engine Oils
ASTM D4742 Standard Test Method for Oxidation Stability of Gasoline Automotive Engine Oils by Thin-Film Oxygen Uptake (TFOUT)
6. Apparatus
6.1 High Pressure Reactor, glass sample container, aluminum insert, pressure gage, thermometer, test bath and accessories are shown in Fig. 2 and Fig. 3 and described in Annex A1.

NOTE 3 - It is reported in literature that the oxidation high pressure reactor can be modified from the Test Method D2272 oxidation high pressure reactor by insertion of an aluminum cylinder.

6.2 Precision Pressure Gage - A certified precision pressure gage is used to accurately control the oxygen feed to the high pressure reactor. The gage has a sufficient range to encompass 0 to 620 kPa (90 psig) required by the test method with division 3.4 kPa (0.5 psig) or better to enable readings to be made to 1.7 kPa (0.25 psig).

7. Reagents
7.1 Purity of Reagents - Reagent grade chemicals shall be used 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.

7.2 Purity of Water - Unless otherwise indicated, references to water shall be understood to mean distilled water meeting requirements of reagent water as defined by Type I of Specification D1193.

7.3 Acetone, CH3COCH3.

NOTE 4 - Warning: Extremely flammable. Irritating to skin, eyes, and mucous membranes.

7.4 Air, containing 2000 ppm nitrogen dioxide, NO2 (commercially available compressed gas mixture, certified within +/-5 %).

NOTE 5 - Warning: Nitrogen dioxide is poisonous.

7.5 n-Hexane, C6H14, Practical Grade.

NOTE 6 - Warning: Extremely flammable. Harmful if inhaled. May produce nerve cell damage. Skin irritant on repeated contact. Aspiration hazard.

7.6 Isopropyl Alcohol, CH3CH(CH3)OH.

NOTE 7 - Warning: Flammable. Eye irritant. Vapors narcotic.

7.7 Oxygen.

NOTE 8 - Warning: Oxygen vigorously accelerates combustion.

7.8 Potassium Hydroxide, Alcohol Solution (1.5 %) - Dissolve 12 g of potassium hydroxide (KOH) pellets in 1 L of 99 % isopropyl alcohol.

NOTE 9 - Warning: Potassium hydroxide is corrosive.

8. Materials
8.1 Fuel Component - The fuel component is an oxidized nitrated gasoline fraction. The fuel component is available as part of the Standard Reference Materials SRM 1817. This component may be prepared in accordance with the procedures described in Annex A2. (See Note 11 and Note 12.)

NOTE 10 - Warning: Fuel component is extremely flammable. Vapors harmful if inhaled. Skin irritant on repeated contact. Aspiration hazard.

8.2 Soluble Metal Catalyst Mixture - This catalyst is a mixture of soluble metal catalysts (lead, copper, iron, manganese, and tin). The catalyst is available as part of the Standard Reference Materials SRM 1817. The catalyst may be prepared according to the procedures described in Annex A3. (See Note 11 and Note 12.)

NOTE 11 - Warning: Lead and manganese naphthenates are known to be poisonous, but all naphthenates should be handled with care. Naphthenates are also flammable.

NOTE 12 - To ensure stability, both the fuel component and metal catalysts are to be stored in sealed, amber-colored containers under argon, and between 20 to 25°C. Under these conditions, the materials have been found to be stable for at least two years.

NOTE 13 - It is recommended that productions of fuel or metal catalyst mixtures, or both, be correlated with Standard Reference Materials SRM 1817, in accordance with good laboratory practices.

8.3 Liquid Detergent (Industrial Strength).

8.4 Silicone Stopcock Grease.