ASTM D2893 for oxidation characteristics of extreme-pressure lubrication oils
5. Apparatus
5.1 Heating Bath or Block, thermostatically controlled, capable of maintaining the oil sample in the test tube at a temperature of 95 more or less 0.2°C (Test Method A), or 121 more or less 1.0°C (Test Method B) and large enough to hold the desired number of oxidation cells immersed in the heating bath or block to a depth of approximately 350 mm. The liquid heating bath shall be fitted with a suitable stirring device to provide a uniform temperature throughout the bath.
5.2 Test Tubes, of borosilicate glass, 41 more or less 0.5 mm inside diameter and 600 mm in length are required, each fitted with a slotted cork (Note 2) stopper into which shall be inserted a glass air delivery tube of 4 to 5 mm of inside diameter. The length of the air delivery tube shall be such that one end reaches to within 6 mm of the bottom of the tube and the other end projects 60 to 80 mm from the cork stopper.
NOTE 2 - New corks should be used for each run.
5.3 Flowmeter, one to each test tube, capable of measuring an air flow of 10 L/h with an accuracy of 60.5 L/h.
5.4 Thermometer - ASTM Solvent Distillation Thermometer having a range from 76 to 126°C and conforming to the requirement for Thermometer 40C as prescribed in Specification E 1. Alternatively, calibrated thermocouples may be used.
5.5 Air Supply - Oil-free, dried air at constant pressure shall be supplied to each flowmeter.
5.6 Air Dryer - Before being supplied to the flowmeters, the air shall be passed through a drying tower packed with indicating grade of anhydrous calcium sulfate or equivalent. The quantity of dessicant should be sufficient to last for the entire test.
