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
|Published (Last):||6 October 2013|
|PDF File Size:||9.54 Mb|
|ePub File Size:||18.73 Mb|
|Price:||Free* [*Free Regsitration Required]|
If a precision experiment is performed using the uniform level design described in IS0in which each laboratory is sent one hide at each level of the experiment, and two test results are obtained on each hide, variation 57725-5 hides 5725-55 add to the between-laboratory variation, and so increase the reproducibility standard deviation. To analyse the data using the robust methods described here, ‘Algorithm A is applied to the cell averages, and ‘Algorithm S’ is applied to each series of ranges in turn.
ISO Accuracy of Measurement Methods and Results Package
Basic oso for the determination of repeatability and reproducibiiity of 7525-5 standard measurement method. It provides a convenient method of applying robust analysis to precision experiments with more than two factors such as the design for a heterogeneous material in clause 5 of this part of IS0and the staggered-nested designs of IS0 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.
For test results, numbering in the order of increasing 572-55 Additional symbols and abbreviations used in IS0 D Within-cell difference in a split-level experiment Number of samples laboratory at one level tested in a 0.
All standards are subject to revision, and parties to agreements based on this part of IS0 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.
There are robust methods that combine test results within cells in a robust manner, and they would be more complicated to apply in practice. The between-sample ranges are smaller than the between-test-result ranges, suggesting that variation between samples is not important, at Level 6.
BS ISO 5725-5:1998
Figure 2 does not reveal any noteworthy pattern. It is incorrect to use such a test to decide if the variation between samples can be ignored in the analysis so that the test results in each cell are treated as if they are all obtained on the same sample. Basic method for the determination of repeatability and reproducibility of a standard measurement method Part 3: Because of the natural variability of jso material, there will always be some variability between bulk samples of the same product.
The corresponding formulae for the split-level experiment are set out below. It is possible to generalize this simple design, by allowing for more than two samples per laboratory per level, or for more than two test results per sample.
Some participants in a precision experiment may achieve poor repeatability when a measurement method is subjected to a precision experiment for the first time, or when they have little experience of the measurement method, and these are situations when the use of robust methods will be particularly appropriate.
Calculation of the sum of squares for samples i 1 Sum of squares for Degrees of freedom for samples: At the time of publication, the editions indicated were valid.
The values for all levels are plotted in figures 5 to 7. For an experiment with a heterogeneous material, this model is expanded to become: If outliers are present in the data 5725–5 these will inflate the denominators and produce a distorted effect in the graphs of the statistics.
The general case is considered in 5.
In the sand example discussed in 5. A common test that is applied to leather is a tensile strength test in BS i The p participating laboratories are each provided with two samples at q levels, and obtain two test results on each sample.
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 ios range that was shown to be a nearstraggler by Cochran’s test.
A design for a heterogeneous material Robust analysis for a particular level of an experiment on a heterogeneous material 6. Also, the figure 3 showed a consistent negative bias in the results from Laboratory 5.
To test for stragglers and 5275-5 in the cell averages, apply Grubbs’ tests to the values in each column of table 3 in turn. The Analyst,pp. However, when the aim of the precision experiment is to discover the variability that will be experienced in practice for example, when vendors and purchasers test samples of the same product then it is necessary for the variability arising as a consequence of the heterogeneity of the 57255- to be included in the measures of the precision of the measurement method.
Page 17, Equations 25 and 26 in Subclause 5. Royal Society of Chemistry, London. Your basket is empty.