ASTM D4047 Standard Test Method for Phosphorus in Lubricating Oils and Additives by Quinoline Phosphomolybdate Method
10. Report
10.1 Report result to three significant figures as the Phosphorus Content, ASTM D4047/IP 149.
11. Quality Control
11.1 Confirm the performance of the test procedure by analyzing a quality control sample which is stable and representative of the sample of interest.
11.1.1 When the quality control/quality assurance protocols are already established in the testing facility, these may be used to confirm the reliability of the test result.
11.1.2 When there is no quality control/quality assurance protocol established in the testing facility, Appendix X1 can be used to perform this function.
12. Precision and Bias
12.1 The precision of this method as obtained by statistical examination of interlaboratory results6 is as follows:
12.1.1 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 only one case in twenty, where x = average of the two test results.
12.1.2 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, in the normal and correct operation of the test method, exceed the following values in only one case in twenty, where x = average of the two test results.
12.2 Precision is given in Table 2 for typical values of x. These precision values have been obtained by statistical examination of interlaboratory results and are published for the first time in 1979.
12.3 Bias - The bias of this test method cannot be determined since an appropriate standard reference material containing a known level of phosphorus in liquid petroleum hydrocarbon is not available.
13. Keywords
13.1 additives; lubricating oils; phosphomolybdate; phosphorous