ISO 英文 – INTERNATIONAL STANDARD IS0 TECHNICAL CORRIGENDUM 1 Published ISO Accuracy (Trueness and Precision) of Measurement Methods and Results – Part 5: Alternative Methods for the Determination of the Precision of a. Find the most up-to-date version of ISO at Engineering
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Your basket is empty. These data 525-5 reproduced here in table This is laid down, by the action of wind or water, in strata that always contain graduations in particle size, so when sand is used the particle size distribution is always of interest.
If the calculations are being done by hand, the data analyst should use the direct method described in 6. The second term on the right-hand side of 8. The interpretation of these tests is discussed fully in subclause 7.
It is therefore recommended that they are used for this purpose. The analysis of variance. A split-level experiment – Determination of protein which involved the determination by combustion of the 4.
The sample effects for each i and r with summation over k: This part of 57255 should be read in conjunction with IS0 because the underlying definitions and general principles are given there. B informative Derivation of isi factors used in algorithms A and S Figure 6 shows that three laboratories 1, io and 10 obtained high k statistics for between-sample ranges: A common test that is applied to leather is a tensile strength test in BS i Page 17, Equations 25 and 26 in Subclause 5.
Robust analysis for a particular level of a uniform-level design Calculation of the sum of squares for samples i 1 Sum of squares for Degrees of freedom for samples: Figure 5 shows that Laboratory 6 obtained several high k statistics for between-test-result ranges, indicating that it has poorer repeatability than the other laboratories. Accept and 5725- Learn more about the cookies we use and how to change your settings.
As the voice of the U. Level 5 in that example is of particular interest because Laboratory 1 gave a cell average that was shown to be a near-straggler by Grubbs’ test, and Laboratory 6 gave a cell range that was shown to be a nearstraggler by Cochran’s test. This would arise if the participating laboratories in a precision experiment were each sent a single sample of a homogeneous material, were asked to ido out two oso perhaps more tests 572-55 sample, and if each test involved a number of determinations and the test result is calculated as the average of the determinations.
If the participants in the experiment can be considered to be divided into two classes, those that produce good-quality data, and those that produce poor-quality data, then the robust methods should yield values for the repeatability and reproducibility standard deviations that are valid for the good-quality-data class, and not affected by the poor-quality data provided that the poor-quality-dataclass is not too large.
ISO Accuracy of Measurement Methods and Results Package
The two samples within a level are denoted U and 6,where a represents a sample of one material, and b represents a sample of the other, similar, material. This is a small difference, so table 1 and figures B. It is also necessary to specify the number of determinations that are to be averaged to give a test result, because this affects the values of the repeatability and reproducibility standard deviations.
Use in practice of accuracy values – – Parts 1 to 6 of IS0 together cancel and replace IS0which has been extended to cover trueness in addition to precision and intermediate precision conditions in addition to repeatability conditions and reproducibilityconditions. Subscription pricing is determined by: The general case is considered in 5. The estimate of the between-laboratorystandard deviation is thus, from equation 72 in 6.
In many chemical analysis methods, the matrix containing the constituent of interest can influence the precision, so for a split-level experiment two materials with similar matrices are required at each level of the experiment. Option b wastes data, but allows the simple formulae to be used. This does not raise any issues that have not already been covered in IS0so it will not be considered here.
To obtain the reproducibilitystandard deviation, use equation 76 in 6. Industrial Quality Control, 15,pp. The data for Level 14 see table 4 are used here to illustrate the results that are obtained by robust analysis.
You can download and open this file to your own computer but DRM prevents opening this file on another computer, including a networked server. Journal of the Association of Official Analytical Chemists, 72, ,pp.
This is useful when it is possible to investigate the causes of the largest laboratory biases with the aim of taking izo action. Because the number of replicates in a split-level experiment is, lso effect, this number of two, it is not possible to reduce the uncertainty of the estimate of laboratory bias by increasing the number of replicates. Figure 4 shows that, in this experiment, at Level 6, there is wide variation between the cell averages, so that, if the test method were to be used in a specification, it is likely that disputes would arise between vendors and purchasers because of differences in their results.
Excluding outliers can sometimes have a large effect on the estimates of repeatability and reproducibility standard deviations, but in practice, isk applying the outlier tests, the data analyst may have to use judgement to decide which data to exclude.
BS ISO 5725-5:1998
57255- General principles and definitions Part 2: Page 38, Equation 72 in Subclause 6. If it is decided that a between-sample range is an outlier, or that a cell average is an outlier, and that the results that give rise to such an outlier are to be excluded, then exclude all the test results for the appropriate cell from the calculation of the repeatability and reproducibilitystandard deviations.
It is necessary, for a split-level experiment, that the two sirnilar materials used at a level of the experiment are so simitar that they can be expected to give the same repeatability and reproducibility standard deviations. The robust methods described in this clause allow the data to be analysed in such a way that it is not required to make decisions that affect the results of the calculations.