ASTM D5827 Standard Test Method for Analysis of Engine Coolant for Chloride and Other Anions by Ion Chromatography
12. Reporting of Results
12.1 Report the concentration of anions found in the sample, sample analysis date, and analyst.
13. Precision and Bias
13.1 Precision - The precision of this test method is based on interlaboratory study of D5827, Standard Test Method for Analysis of Engine Coolant for Chloride and Other Anions by Ion Chromatography, conducted in 2008. Each of seven laboratories performed three analyses on ten different materials. Every "test result" represents an individual determination. The laboratories obtained two replicate test results for each material. Practice E691 was followed for the design and analysis of the data; the details are given in ASTM Research Report No. D15-1025.
13.1.1 Repeatability Limit (r) - Two test results obtained within one laboratory shall be judged not equivalent if they differ by more than the "r" value for that material; "r" is the interval representing the critical difference between two test results for the same material, obtained by the same operator using the same equipment on the same day in the same laboratory.
13.1.1.1 Repeatability limits are listed in Tables 3-5.
13.1.2 Reproducibility Limit (R) - Two test results shall be judged not equivalent if they differ by more than the "R" value for that material; "R" is the interval representing the critical difference between two test results for the same material, obtained by different operators using different equipment in different laboratories.
13.1.2.1 Reproducibility limits are listed in Tables 3-5.
13.1.3 The above terms (repeatability limit and reproducibility limit) are used as specified in Practice E177.
13.1.4 Any judgment in accordance with statements 13.1.1 and 13.1.2 would have an approximate 95 % probability of being correct.
13.2 Bias - At the time of this study, no accepted reference material suitable for determining bias was reported for this test method, therefore no statement on bias is being made.
13.3 The precision statement was determined through statistical examination of 420 results, from seven laboratories and ten materials.
13.4 To judge the equivalency of two test results, it is recommended to choose the material closest in characteristics to the test material.
14. Keywords
14.1 chloride; chromatography methods; engine coolant; ion chromatography
