ASTM D6514 Standard Test Method for High Temperature Universal Oxidation Test for Turbine Oils
6. Apparatus
6.1 Heating Block, as shown in Fig. 1, and as further described in Guide D4871, to provide a controlled constant temperature for conducting the test.
6.1.1 Test cells are maintained at constant elevated temperature by means of a heated aluminum block which surrounds each test cell. Alternate apparatus designs for sample heating and for temperature and flow control shall be acceptable, provided they are shown to maintain temperature and gas flow within the standard's specified limits.

6.1.2 Holes in the aluminum block to accommodate the test cells shall provide 1.0 mm maximum clearance for 38-mm outside diameter glass tubes. The test cells shall fit into the block to a depth of 225 +/- 5 mm.

6.2 Temperature Control System , as shown at lower left in Fig. 1, and as further described in Guide D4871, to maintain the test oils in the heating block at 155 +/- 0.5°C for the duration of the test.

6.3 Gas Flow Control System, as shown at the upper left in Fig. 1, and as further described in Guide D4871, to provide dry air at a flow rate of 3.0 +/- 0.5 L/h to each test cell.
6.3.1 A gas flow controller is required for each test cell.

6.3.2 Flowmeters shall have a scale length sufficiently long to permit accurate reading and control to within 5 % of full scale.

6.3.3 The total system accuracy shall meet or exceed the following tolerances:
6.3.3.1 Inlet pressure regulator within 0.34 kPa (0.05 psig) of setpoint; total flow control system reproducibility within 7 % of full scale; repeatability of measurement within 0.5 % of full scale.

6.4 Oxidation Cell, borosilicate glass, as shown in Fig. 2, and as further described in Guide D4871. This consists of a test cell of borosilicate glass, standard wall, 38 mm outside diameter, 300 +/- 5-mm length, with open end fitted with a 34/45 standard-taper, ground-glass outer joint.

6.5 Gas Inlet Tube, as shown in Fig. 2, and as further described in Guide D4871. This consists of an 8-mm outside diameter glass tube, 455 +/- 5 mm long, lower end with fused capillary 1.5-mm inside diameter. The capillary bore shall be 15 +/- 1 mm long. The lower tip is cut at a 45° angle.

6.6 Basic Head, as shown in Fig. 3, and as further described in Guide D4871. This is an air condenser, with 34/45 standard-taper, ground-glass inner joint, opening for gas inlet tube, septum port for sample withdrawal, and exit tube to conduct off-gases and entrained vapors. Overall length shall be 125 +/- 5 mm.

6.7 Test precision was developed using the universal oxidation/thermal stability test apparatus described in Guide D4871. Alternate apparatus designs for sample heating, and for temperature and flow control shall be acceptable provided they are shown to maintain temperature and gas flow within the specified limits.

6.8 Drying Oven, explosion proof model recommended.

7. Reagents and Materials
7.1 Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents 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 Catalyst Coil (comprised ofthe following):
7.2.1 Low-Metalloid Steel Wire, 1.59 mm in diameter (No. 16 Washburn and Moen Gage). Carbon steel wire, soft bright annealed and free from rust, of grade 1008 as described in Specification A510, is preferred. Similar wire conforming to British Standard BS 1829 is also satisfactory.

7.2.2 Electrolytic Copper Wire, 1.63 mm in diameter (No. 14 American Wire Gage or No. 16 Imperial Standard Wire Gage), 99.9 % purity, conforming to Specification B1, is preferred.

7.3 Acetone, reagent grade. (Warning - Flammable. Health hazard.)

7.4 Heptane, reagent grade. (Warning - Flammable. Health hazard.)

7.5 Propan-2-ol (iso-Propyl Alcohol), reagent grade. (Warning - Flammable. Health hazard.)

7.6 Isooctane, reagent grade. (Warning - Flammable. Health hazard.)

7.7 Abrasive Cloth, silicon carbide, 100-grit with cloth backing.

7.8 Whatman Filter Paper, No. 41, 47-mm diameter.

7.9 Membrane Filters, white, plain, 47 mm in diameter pore size 8 µm. Millipore SC membrane filters (MF-type, cellulose ester), or equivalent have been found satisfactory.

7.10 Air, dry.

7.11 Cleaning Reagent, either Nochromix (Warning - Health hazard. Corrosive. Harmful if inhaled) or Micro solution.

NOTE 1 - Because ofextreme hazards, chromic acid cleaning solution is not recommended.