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
9. Procedure
9.1 Fill a sample cell nearly full with a portion of the sample to be analyzed. Follow the manufacturer's recommendation to ensure that the cell is full enough such that X-ray count rate does not depend on the amount of sample in the cell. Make sure that no wrinkles or bulges are present in the film. The film must be flat. The cell shall be vented, by cutting a hole in the top, if necessary.
9.2 Place the sample cell in the X-ray beam to measure and record the intensity for each element and scatter region in each calibration standard in accordance with the conditions set by following 8.1.
10. Calculation
10.1 Set the instrument's software to calculate the results in mass % to three decimal places.
