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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Robust analysis for a particular level of a split-level design You can download and open this file to your own computer but DRM prevents opening this file on another computer, including a networked server.

Basic method for the determination of repeatability and reproducibiiity of a standard measurement method. An additional question has to be considered: To check the consistency of the between-test-result ranges, calculate the k statistics as: Also in this design, the cell standard deviations are pooled to give an estimate of the repeatability standard deviation. For example, with 5725-55 data from one level of the uniform-level design considered in IS0the first stage of the analysis is to calculate the average and standard deviation of the measurement results in each cell.

The first term on the right-handside of equation 8.

Assemble the data into a table as shown in table 9. However, the h statistics for all the other laboratories for that level will be small, even if some of these other laboratories give outliers.

Using equations 21 to 26 given in 5. It may be confirmed that this is indeed the case, so that a valid solution has been obtained.

### ISO Accuracy of Measurement Methods and Results Package

It also specifically provides a procedure for obtaining intermediate measures of precision, basic methods for the determination of the trueness of a measurement method, the determination 57255-5 repeatability and reproducibility of a kso measurement method. It is common to find 572-55 sort of pattern when plotting the data from a split-level design as in figure 1.

Wiley, New York, The corresponding formulae for the split-level experiment are set out below. A method that is used to measure their ability to do this is the magnesium sulfate soundness test [21, in which a test portion of aggregate is subjected to a number of cycles of soaking in saturated magnesium sulfate solution, followed by drying.

Reference number IS0 If a laboratory is reporting generally biased results, then most of the h statistics for the laboratory, in the graph derived from the cell averages, will be large and in the same direction.

Royal Society of Chemistry, London. If the document is revised or amended, you will be notified by email.

## BS ISO 5725-5:1998

In the same figure, Laboratories 8 and 9 gave h statistics that are nearly all positive, indicating consistent positive biases in their data but smaller than the negative bias in Laboratory 5. In practice it is often found that some laboratories achieve poorer repeatability than others.

This would introduce a bias into the estimation of the repeatability standard deviation, because finding that the variation between samples i s not statistically izo does not prove that the variation between samples is negligible. However, if ios laboratory is sent two hides at each level, and two test results are obtained on each hide, the data can be used to estimate the variation between hides and to calculate a value for the reproducibility standard deviation of the test method from which the variation between-hides has been removed.

Hence, in IS0 Consistency check on between-test-result ranges grouped by laboratory c l n m 1 2 3 4 5 L 6 Laboratory 7 lild 8 9 10 1 1 Figure 6 – Example 2: Figure 2 does not reveal any noteworthy pattern. Option a is to be preferred. The interpretation of these graphs is discussed fully in subclause 7. You may delete a document from your Alert Profile at any time.

We use cookies to make our website easier to use and to better understand your needs. For an experiment with a heterogeneous material, this model is expanded to become: Graphs of this type give an easily understood picture of the amount of variation arising from the different sources between test results, between samples, and between laboratories.

Company organization, management and quality. In many chemical analysis methods, the matrix containing the constituent of interest can influence the precision, so for a split-level experiment 5725–5 materials with similar matrices are required at each level of the experiment. The use of robust estimates of the standard deviations as the denominators in the h and k statistics, and of robust estimates of the overall averages in the calculation of the h statistics, avoids this distortion.

The samples were approximately kg in mass they were used 5725–5 a number of other testsand the test portions were approximately g in mass. To assess the uncertainty of the estimate of a laboratory bias in a split-level experiment, calculate the quantity Aas defined by equation 16 of IS0 W t h cadi, tevet, t w o feeds were used having similar mass fraction of protein in feed.

Laboratory 5 gives a point in the bottom left-hand corner of the isp, and Laboratory 1 gives a point in the top right-hand corner: The formulae presented in 5.