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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Need more than one copy? International organisations, governmental and non-governmental, in liaison with ISO, also take pari in the work. This may be unsatisfactory.
BS ISO 5725-5:1998
However, the above equation may be derived by replacing p in equation 9 of IS0 Reference number IS0 The symbols used in IS0 are given in annex A.
Laboratory 5 gives only one cell average at Level 10 that is sufficiently extreme to be classed as an outlier by Grubbs’ test, but gives three other stragglers, and a strong indication in figure 3 that something is amiss in this laboratory. With eiiher approach that described in IS0 or that described herethe two measures are then used to calculate estimates of the repeatability and reproducibility standard deviations in the same way.
If the calculations are being done by hand, the data analyst should use the direct method described in 6. The design for a heterogeneous material given in this part of IS0 yields information about the variability between samples which is not obtainable from the basic method; it may be used to calculate 5275-5 estimate of reproducibilityfrom which the between-sample variation has been removed.
In an experiment on a heterogeneous material, the results of applying these tests should be acted on in the following order. For example, with the 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.
Calculate the cell differences Dg. This extra information may be valuable.
To obtain the reproducibilitystandard deviation, use equation 76 in 6. Search all products by. Calculation of the sum of squares for samples i 1 Sum of squares for Degrees of freedom for samples: This would arise if the participating laboratories in a precision experiment were each sent a single sample of a homogeneous material, were asked to carry out two or perhaps more tests per sample, and if each test involved a number of determinations and the test result is calculated as the average of the determinations.
In the split-level design, each participating laboratory is provided laboratory standard deviation c with a sample of each of two similar materials, at each level of the experiment, and the operators are told that the samples are not identical, but they are not told by how much the materials differ.
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.
This would introduce a bias into the 575-5 of the repeatability standard deviation, because finding that the variation between samples i s not statistically significant does not prove that the variation between samples is negligible.
To test for stragglers and outliers in the cell averages, apply Grubbs’ tests to the values in each column of table 3 in turn. Examine the data for consistency using the h and k statistics, described in subclause 7. This is why it is important that the two materials should be similar. Laboratory 5 gives a point in the bottom left-hand corner of the graph, and Laboratory 1 gives a point in the top right-hand corner: 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 izo drying.
ISO Accuracy of Measurement Methods and Results Package
Please download Chrome or Firefox or view our browser tips. This is performed on dumbell-shaped specimens Isk specifies the number of such specimens to cut from a hide, and also their position and orientation within the hide, so the natural definition of a “sample” to use when testing leather is a complete hide.
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 The solution may also be derived directly, as follows.
Option b wastes data, but allows the simple formulae to be used. To assess the uncertainties of the estimates of the repeatability and reproducibility standard deviations, calculate the following quantities. B informative Derivation of the factors used in algorithms A and S Plot these statistics to show up inconsistent laboratories, by plotting the statistics in the order sio the levels, but also grouped by laboratory. It is reasonable to assume that the variation between samples is random, does not depend on the laboratory, but may depend on the level of the ido, so the term Hiil has a zero expectation, and a variance: Find Similar Items This product falls into the following categories.