ASTM D5966 Test Method for Evaluation of Engine Oils for Roller Follower Wear
ASTM D5966 Standard Test Method for Evaluation of Engine Oils for Roller Follower Wear in Light-Duty Diesel Engine
11. Final Test Report
11.1 Reporting Calibration Test Results - Report all calibration (reference oil) tests to the TMC within five days of test completion. Facsimile transmit Fig. A5.1, Fig. A5.2, Fig. A5.3, Fig. A5.17, and Fig A4.1 (reference Annex A5) to the ASTM TMC. A copy of the final test report (all forms) should be submitted by mail to the test developer and the TMC within 30 days of test completion (reference X1.1).
11.2 Report Forms - The final report forms are shown in Annex A5. These forms are to be used for both calibration and non-reference tests. Use the Data Dictionary formats as shown in Annex A5 to report test values.
11.2.1 Electronic Data Transmission of Test Results - Annex A5 contains the RFWT and Header Data dictionaries. Additional information is also provided for its use. This information is provided to anyone wishing to transmit test information electronically. For more information on electronic transmissions, contact the TMC.
11.3 Interim Non-Valid Calibration Test Summary (not shown in Annex A5) - This information includes test run number, test start and completion dates, the blind oil code, the industry oil code, the reason the test was not acceptable, the corrective action, and any other pertinent information. Include this information in the comments section of Fig A4.1. Include a comment for each non-valid or aborted calibration test in a series.
11.4 Severity Adjustments - This test incorporates the use of a Severity Adjustment (SA) for non-reference test results. A control chart technique, described in 11.4.1 and 11.4.2, has been selected for the purpose of identifying when a bias becomes significant for Roller Follower Shaft Wear. When a significant bias is identified, a SA is applied to non-reference test results. The SA remains in effect until subsequent calibration test results indicate that the bias is no longer significant. SAs are calculated and applied on a laboratory basis.
11.4.1 Control Chart Technique For Severity Adjustments (SA) - Standardized calibration test results are applied using an exponentially weighted moving average (EWMA) technique. Values are standardized to delta/s ((result - target)/standard deviation). The targets and standard deviations for current calibration oils are published by the ASTM TMC. Include all operationally valid calibration tests in a laboratory control chart. Chart tests in order of completion. Record completion of tests by EOT date and time. EOT time is reported as hour and minute (Central Time) according to the 24-h clock (1 am = 1:00, 1 pm = 13:00). Reporting test completion time enables the TMC to properly order tests that are completed on the same day for industry plotting purposes. Report calibration tests to the TMC in order of test completion. A minimum of two tests is required to initialize a control chart.
11.4.2 Calculate EWMA values using the following equation:
Zi = 0.2(Yi) + 0.8(Zi-1)
where:
Z0 = 0,
Yi = standardized test result, and
Z = EWMA of the standardized test result at test order i.
If the absolute value of EWMA, rounded to three places after the decimal, exceeds 0.600 then apply an SA to subsequent non-reference results.
11.4.3 Calculation of Severity Adjustment - The following example illustrates how to compute and apply EWMA and SA values. Please note, that test targets are presented for examples only.
Roller Follower Shaft Wear SA
TMC Oil 1004
Applicable Test Targets:
Mean = 0.41
Standard Deviation 5 0.07
Z1 = -0.400
Test Result:
T2 = 0.30
Standard Test Result:
Y2 = (Ti - Mean)/Standard Deviation = -1.571
EWMA: Z2 = 0.2(Y2) + 0.8(Z1) = -0.634
11.4.3.1 Since ||-0.634|| > 0.600, apply an SA: SA = (-1) (EWMA) (standard deviation). Round this result to two decimal places. Enter this number on Fig. A5.2 under the non-reference oil test block in the space for severity adjustment. Add this value to non-reference average wear results. Enter the adjusted wear value in the appropriate space. An SA will remain in effect until the next calibration test. At that time, calculate a new EWMA.
12. Precision and Bias
12.1 Reference Oil Precision and Reproducibility - The TMC determines estimates of precision from calibration test results. These precision data are periodically updated and are available from the TMC.
12.2 Table 6 below shows the precision data (repeatability and reproducibility) for the Roller Follower Wear Test. Data was obtained from April 1993 through April 1995.
12.3 Bias - Bias is determined by applying an accepted statistical technique to reference oil test results and when a significant bias is determined, a severity adjustment is permitted for non-reference oil test results (see 11.4).
13. Keywords
13.1 calibrate; diesel engine; engine oil; light-duty; light-duty engine; lubricant; reference oil; roller follower shaft wear; used oil wear
