ASTM D972 Test Method forEvaporation Loss of Lubricating Greases and Oils
6. Apparatus
6.1 Evaporation Cell, (Fig. 1) as described in Annex A1.
6.2 Air Supply System, capable of supplying to the cell the required flow of air free of entrained particles. A400 mm (16-in.) length of 25-mm (1-in.) diameter pipe packed with glass wool has been found satisfactory for filtering the air.
6.3 Oil Bath, shown in Fig. 1a and described in Annex A1.
NOTE 3 - Other constant-temperature baths may be used if they are equivalent in heat capacity and thermal gradient characteristics to the oil bath.
6.4 Thermometers - For tests at 100°C (210°F) an ASTM Thermometer having a range from 95 to 103°C (204 to 218°F) and conforming to the requirements for Thermometer 22C-86 (22F-86) as prescribed in Specification E 1 shall be used. For tests at temperatures above 100°C (210°F) an ASTM Precision Thermometer conforming to the requirements for Thermometer 67C-86 (67F-86) as prescribed in Specification E 1 is suitable.
6.5 Flowmeter - A rotameter calibrated to deliver air at a rate of 2.58 +/- 0.02 g/min between 15 and 30°C (60 and 85°F) (2 L/min at standard temperature and pressure). It shall be furnished with a needle valve and mounted as shown in Fig. 1.
7. Sampling
7.1 Each grease test will require approximately 20 g to fill the sample cup for a single cup for a single run. Therefore, the sample presented for analysis should be large enough to make possible the selection of a representative portion for testing. Examine the sample for any indication of non-homogenity such as oil separation, phase changes, or gross contamination. If any abnormal conditions are found, obtain a new sample.
7.2 Each oil test will require at least 10 g of sample for a single run. Therefore, sufficient sample should be available to observe any gross contamination or phase separation. If any abnormal conditions are found, obtain a new sample.
8. Preparation of Apparatus
8.1 Clean and inspect all components and particularly for wear or damage to threads on sample cups and hood assemblies. Repair or replace if mating is impaired.
8.2 Verify unrestricted air flow through tubing on test cell and through education tube through cover.
8.3 Check that the oil bath is at the designated level.
8.4 Check flowmeter before running any test if there is doubt of its accuracy.
