11.1 Precision - An interlaboratory study performed in 2008 by 13 laboratories (9 using glass baths and 4 using metal baths). At 54°C, the following samples were included: Turbine Oil, Mineral Turbine Oil ISO 32, 150 N Base oil (in duplicate), Mineral Circulating Oil ISO 32, Synthetic Gear Oil ISO 32, Industrial Oil ISO 68, Industrial Oil ISO 68, Synthetic Compressor ISO 46, Multi-Purpose Oil ISO 32. At 84°C, the following samples were included: 600 NS Base oil , Synthetic Gear Oil ISO 320 (in duplicate), Synthetic Paper Machine Oil ISO 220, Industrial Oil ISO 100, Hydraulic oil ISO 150, Synthetic Compressor ISO 100, Multi-Purpose Oil ISO 100, Circulating Oil, Circulating Oil. The mineral oil samples were Group I or Group II based. The synthetic samples were primarily PAO based but may have contained some amount of a Group V oil, however no specific details on any co-base oil was disclosed. This precision is for the determination of the time in minutes to 3 mL of emulsion or 37 mL of water.
11.1.1 Repeatability - The difference between successive test results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the following values only in one case in twenty.
11.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the following values only in one case in twenty:
11.2 Bias - The procedure in this test method for measuring water separability has no bias because the value for water separability is defined only in terms of the test method.
12. Keywords
12.1 emulsion; petroleum oils; steam-turbine oils; synthetic fluids; water separability