REASONS FOR PROFICIENCY TESTING
Proficiency testing is carried out since even in a well organised, accredited laboratory with the best staff and best equipment anomalous results may still occur. It is also possible that a standardized method, validated by precision tests may contain errors that are surfaced after several rounds of a proficiency testing scheme. The requirement for participation in proficiency testing not only lends confidence to laboratory performance but also for customers and accreditation bodies. Other reasons for the use of proficiency testing includes evaluation of laboratory performance for specific tests, initiation of corrective action where and when appropriate, establishment of effectiveness and comparability of differing test methods, identification of interlaboratory differences, education of participating laboratories where appropriate and validation of any uncertainty of measurement claims.
The results obtained by the participating laboratory are submitted to the Proficiency testing coordinator who collates all the results from the participants. Statistical analysis such as an outlier test, the average, standard deviation, robust average, robust standard deviation, uncertainty of measurement and z-scores are calculated. A report is compiled for each of the participants detailing their performance, possible problem areas and conclusions. The participant uses this information to rectify any areas of concern highlighted by the scheme.
FREQUENTLY ASKED QUESTIONS
• When should I report my results?
As soon as possible, but by the 25th of the month at the latest
• When should I analyse my sample?
It should be analysed as soon as possible in order to prevent any oxidation/degradation of the sample
• Q: How do I report my results
A: Report in the same format as you would for a client
• Q: What is moisture corrected Volatile Matter?
A: Volatile Matter as analysed – MIAS = Moisture Corrected Volatile Matter
• Q: What is moisture corrected Hydrogen?
A: Hydrogen as analysed – (0.1119 x MIAS) = Moisture corrected Hydrogen
• Q: How many times should the sample be analysed?
A: Samples are to be treated as routine samples in your laboratory. Clearly state which results is to be reported e.g. average result
• Q: How is the Z-Score calculated?
A: Z-Scores are calculated on Dry Base results
Calculation: (Laboratory Result – Average Result) / Standard Deviation
• Q: Why is my Z-Score calculation not the same as the reported Z-Score Calculation?
A: Calculations reported are done on excel. Excel does not round off values, all decimals are taken into consideration.
When the laboratory calculates the Z-Score , the factors (Average, Std deviation and Dry Base result) are rounded to 2 decimal places.
PROFICIENCY TEST REPORTS
|ASH PT RESULTS||HGI PT RESULTS||COAL PT RESULTS||AI PT RESULTS|
|SEMI-PREPARED PT||FLOAT AND SINK PT||COKE PT RESULTS|