ASTM D4927 Method for Elemental Analysis of Lubricant and Additive Components
ASTM D4927 Standard Test Methods for Elemental Analysis of Lubricant and Additive Components - Barium, Calcium, Phosphorus, Sulfur, and Zinc by Wavelength-Dispersive X-Ray Fluorescence Spectroscopy
20. Quality Control
20.1 Confirm the performance of the test procedure by analyzing a quality control (QC) sample (Section 12 for test method A or Section 18 for test method B).
20.1.1 When QC/Quality Assurance (QA) protocols are already established in the testing facility, these may be used to confirm the reliability of the test result.
20.1.2 When there is no QC/QA protocol established in the testing facility, Appendix X1 can be used as the QC/QA system.
21. Precision and Bias
21.1 The precision of these test methods as determined by the statistical examination of the interlaboratory test results is as follows:
21.1.1 Repeatability - The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test materials would, in the long run, in the normal and correct operation, exceed the following values only in one case in twenty.
21.1.1.1 Test Method A - Values can be obtained for each element for any given concentration within the scope of this test method by using the expressions listed in Table 5 or the curves shown in Fig. 1.
21.1.1.2 Test Method B - Values can be obtained for each element for any given concentration within the scope of this test method by using the expressions listed in Table 5 or the curves shown in Fig. 1.
21.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical material would, in the long run, exceed the following values only in one case in twenty.
21.1.2.1 Test Method A - Values can be obtained for each element for any given concentration within the scope of this test method by using the expressions listed in Table 5 or the curves shown in Fig. 1.
21.1.2.2 Test Method B - Values can be obtained for each element for any given concentration within the scope of this test method by using the expressions listed in Table 5 or the curves shown in Fig. 1.
21.2 Bias - The bias for these test methods was not determined since no suitable reference materials of known composition were available.
22. Keywords
22.1 additives; barium; calcium; lubricating oil; phosphorous; sulfur; wavelength-dispersive; X-ray fluorescence; zinc
