ASTM D6443 Copper, Phosphorus and Sulfur in Unused Lubricating Oils and Additives
ASTM D6443 Standard Test Method for Determination of Calcium, Chlorine, Copper, Magnesium, Phosphorus, Sulfur, and Zinc in Unused Lubricating Oils and Additives by Wavelength Dispersive X-ray Fluorescence Spectrometry (Mathematical Correction Procedure)
11. Analysis
11.1 Fit sample cells with film, ensuring that there are no wrinkles or bulges. Fill the cell with sample, to at least three-fourths full. Punch a vent hole in the top of the cell.
11.2 Measure intensities in the same manner as with the calibration standards.
11.3 The analyte concentrations for each sample are calculated from the measured intensities, D values, E values, and alphas, using a model such as Eq 1.
11.4 When a sample contains an analyte at a concentration greater than the corresponding maximum concentration listed in Table 1, dilute the sample appropriately and re-analyze.
12. Quality Control (Required)
12.1 Typically, one or more stable, quality control (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 re-calibration, or both.
12.3 The QC sample precision can be compared with precision of this test method to determine data quality.
