ASTM D7097 Standard Test Method for Determination of Moderately High Temperature Piston Deposits by Thermo-Oxidation Engine Oil Simulation Test - TEOST MHT
17. Report
17.1 For reference oil tests, use the standardized report form set and data dictionary for reporting test results and for summarizing the operation data.
17.2 Report the following to the nearest 0.1 mg:
17.2.1 Filter deposits,
17.2.2 Rod deposits, and
17.2.3 Total deposits (rod deposits plus filter deposits).
NOTE 30 - If desired, report the mass of mantle deposits, volatiles, and recovered oil.
18. Precision and Bias
18.1 Precision:
18.1.1 Repeatability (r) - The difference between successive 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 20 (see Table 1):
r = 0.15(x + 16)
in which (x) is the mean of two test results.
18.1.2 Reproducibility (R) - 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 exceed the following values only in one case in 20 (see Table 1):
R = 0.35(x + 16)
in which (x) is the mean of two test results.
18.2 Bias:
18.2.1 No information can be presented on the bias of the procedure in this test method for measuring deposit mass because no material having an accepted reference value is available.
18.3 General Considerations:
18.3.1 The interlaboratory study on the above precision statement was performed according to this test method with five oils run in duplicate at eleven laboratories. The range of applicability of this test method, as derived from the interlaboratory study, is approximately 10 to 100 mg. For further details, please refer to the research report.
19. Keywords
19.1 deposits; engine oil; oxidation; thermal decomposition; thermal oxidation
