XRF Analyser Manual
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Interpretation of results
If an XRF Analyser measurement is significantly different than expected, it is
recommended that the sample is retested. The following steps may help:
•
Replace the Mylar sheet that covers the detector aperture.
•
Ensure sample is thoroughly mixed before testing.
The XRF Analyser is designed to operate between 15°C and 30°C as stated in the
Technical Specification table. Operation of the XRF Analyser at the limits of, or outside of
this range, may affect the measurement and uncertainty of tests.
It is very important to remember that scientific instruments are unable to report exactly the
same values for consecutive measurements of the same sample. The expected variation
in repeated measurements of the same sample made by the same operator on the same
instrument in the same environment is known as the repeatability. For example, repeated
measurements of a 1.000 % sulphur standard using the Parker Kittiwake XRF Analyser
typically fall within the range 0.983 – 1.017 % nineteen times out of twenty. Of course this
means that some measurements will fall outside this range.
Measurements of identical samples made using different instruments, different operators,
and different environments show a variability characterised by reproducibility. For
example, measurements of the same 1.000 % sulphur standard made using different XRF
analysers on different ships and labs by different operators throughout the world would be
expected to fall within the range 0.935 - 1.065 % nineteen times out of twenty. From this
perspective it is easy to see how a sample sent to a laboratory could test at, for example,
0.95 %, while yielding the result of 1.05 % when measured on a ship.
Please note that the repeatability and reproducibility of sulphur measurements made using
the Parker Kittiwake XRF Analyser are at least as good as those provided in ISO8754. A
degree of result uncertainty is unavoidable.
Although the XRF Analyser reports wear metal concentrations, there is no advice on
suitable pass/fail limits because they tend to be very engine-specific.
Summary of Contents for XRF
Page 1: ...XRF Analyser Instruction manual...
Page 2: ...XRF Analyser Manual...
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