ASTM D3300 Test Method for Dielectric Breakdown Voltage of Insulating Oils
ASTM D3300 Standard Test Method for Dielectric Breakdown Voltage of Insulating Oils of Petroleum Origin Under Impulse Conditions
9. Report
9.1 Report the following information:
9.1.1 Sample identification,
9.1.2 Electrode configuration, polarity, and electrode spacing,
9.1.3 Impulse crest voltage for each breakdown (do not discard any data),
9.1.4 Wave shape identification,
9.1.5 Starting voltage crest level, voltage steps, and highest voltage withstand level,
9.1.6 Mean impulse breakdown value,
9.1.7 Sample water content,
9.1.8 Barometric pressure, and
9.1.9 Date of test.
10. Precision and Bias
10.1 This precision statement applies to new oil received from a supplier. Using the point-to-sphere electrode configuration, the following precision statements are applicable to both positive and negative polarity:
10.1.1 Single Operator Precision - The single operator % coefficient of variance of a single test result comprised of five breakdowns has been found to be 3.9 %. Therefore, results of two properly conducted tests by the same operator on the same sample should not differ by more than 11 % of the average of the two tests. The maximum allowable range for the series of five breakdowns comprising the test result should be less than 33.3 % of the average of the five breakdowns. In the case where a ten-breakdown average is used, the maximum allowable range of the individual tests comprising the result should be less than 54.6 % of the average of the ten breakdowns.
10.1.2 Multilaboratory Precision - The multilaboratory % coefficient of variance has been found to be 5.43 %. Therefore, results of two properly conducted tests in different laboratories on the same sample of oil should not differ by more than 15.4 % of the average of the two results.
10.2 No statement can be made about the bias of this test method because a standard reference material is not available.
11. Keywords
11.1 dielectric breakdown; impulse voltage; insulating oils
