ASTM D2112 for oxidation stability of inhibited mineral insulating oil
ASTM D2112 standard test method for oxidation stability of inhibited mineral insulating oil by pressure vessel
5. Apparatus
5.1 Oxidation Vessel - Glass test specimen container with cover and catalyst coil, pressure gage, thermometer, test bath, and accessories as described in Annex A1. The assembled apparatus is shown in Fig. 1, and its design shown schematically in Fig. 2.

6. Reagents and Materials
6.1 Purity of Reagents - Use reagent grade chemicals in all tests. Unless otherwise indicated, all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available.

6.2 Hydrochloric Acid, 10 vol %.

6.3 Silicon Carbide Abrasive Cloth, 100-grit with cloth backing.

6.4 Acetone, cp.

6.5 2-Propanol, 99 vol %, refined.

6.6 Liquid Detergent.

6.7 Oxygen, 99.5 %, with pressure regulation above 90 psi (620 kPa). (Warning - Oxygen vigorously accelerates combustion).

6.8 Potassium Hydroxide, Alcohol Solution (1 mass %) - Dissolve 7.93 g of potassium hydroxide (KOH) pellets in 1 L of 99 % refined 2-propanol.

6.9 Silicone Stopcock Grease.

6.10 Wire Catalyst - AWG No. 14 (0.0641-in. (1.628-mm) diameter) electrolytic copper wire 99.9 % purity, conforming to Specification B 1. Soft-drawn copper wire of an equivalent grade may also be used.

7. Hazards
7.1 Consult Material Safety Data Sheets for all materials used in this test method.