ASTM D6481 Method for Phosphorus, Sulfur, Calcium, and Zinc in Lubrication Oils
ASTM D6481 Standard Test Method for Determination of Phosphorus, Sulfur, Calcium, and Zinc in Lubrication Oils by Energy Dispersive X-ray Fluorescence Spectroscopy
11. Report
11.1 Report the following information:
11.1.1 Total content for each element, phosphorus, sulfur, calcium, and zinc in mass %.
11.1.2 State that the results were obtained by Test Method D xxxx.
12. Quality Control (QC)
12.1 Typically, one or more stable QC samples that are similar in composition to test samples are analyzed regularly by the testing laboratory. Because data quality requirements can vary among testing laboratories, individual laboratories can determine the frequency of QC sample analysis and the acceptable control limits.
12.2 When QC results are not within control limits, carry out corrective action, such as drift correction or recalibration, or both.
12.3 The QC sample precision can be compared with precision of this test method to determine data quality.
13. Precision and Bias
13.1 Precision - The precision of this test method as obtained by statistical analysis of interlaboratory test results is as follows.
13.1.1 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 in Table 4 in only one case in twenty.
13.1.2 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, exceed the following values in Table 5 in only one case in twenty.
NOTE 5 - The values of the precision estimates for selected values of X, in Tables 4 and 5, are set out in Table 6.
13.2 Bias - No information can be presented on the bias of the procedure in Test Method D xxxx for measuring phosphorus, sulfur, calcium, and zinc because no material having an accepted reference value is available.
14. Keywords
14.1 additive elements; additives; calcium; energy dispersive; lubricating oils; phosphorus; spectrometry; sulfur; X ray; zinc
