ASTM D1934 Standard Test Method for Oxidative Aging of Electrical Insulating Petroleum Oils by Open-Beaker Method
10. Report
10.1 Report the following information:
10.1.1 Designation of this test method (D1934),
10.1.2 Whether or not a metal catalyst was used (Procedure A or B) and the nature and form of the metal catalyst, if used,
10.1.3 Test specimen identification,
10.1.4 Values of the property or properties measured on the aged (and unaged) test specimens, and
10.1.5 Designations of the test methods used to determine the condition of the oil test specimens.
10.1.6 The measured change in mass percent of the oil to validate the test (less than 10 % evaporation).
11. Precision and Bias
11.1 Precision:
11.1.1 The precision of the open-beaker oxidative aging defined by this test method has not yet been adequately defined in accordance with Practice E 177. However, precision estimates for both single-laboratory repeatability and multilaboratory reproducibility of changes in oil dissipation factor (power factor) due to open-beaker oxidative aging are available from a 1958-59 round robin with ten participating laboratories.
11.2 In the case of four naphthenic insulating oils with different viscosities (55, 100, 760, and 2200 SUS at 100°F, and 38, 39, 60 and 105 SUS, respectively, at 210°F) with and without 2.8 cm2 of copper wire catalyst, random errors were proportional to the ratio, Q:
The data were normalized by a logarithmic transformation.
11.3 Repeatability - The standard deviation of the quantity logQ has been estimated to be 0.07 (coefficient of variation of Q = 18 %) for duplicate aging tests run at the same time in a given oven in the same laboratory. The standard deviation of logQ has been estimated to be 0 (coefficient of variation of Q = 60 %) for duplicate aging tests run at different times in the same laboratory.
11.4 Reproducibility - The standard deviation of the quantity logQ has been found to be 0.37 (coefficient of variation of Q = 135 %) for duplicate aging tests run in different laboratories.
11.5 Bias - Since there is no accepted reference material suitable for determining the bias for the procedure in this test method for measuring the true value of the property involved, no statement on bias is being made.
12. Keywords
12.1 aging; electrical insulating oil; open beaker test; oxidative; petroleum