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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This will not be so if some isi of the specimen preparation are shared by several specimens, so that a bias or deviation introduced by the preparation will have a common influence on the test results derived from these specimens. The laboratory effects for each i with summation over r and k: With this design, the first stage of the analysis is to calculate the average of the data for each laboratory at each leveldenoted ri, To test isoo sand, a bulk sample is taken from the product, then one or more test portions are produced from the bulk sample.
ISO Accuracy of Measurement Methods and Results Package
The sample effects for each i and r with summation over k: The basic method requires the preparation of a number of identical samples of the material for use in the experiment. Applying the method of 6. E The repeatability standard aviation srj, between-samples standard deviation sW, between-laboratory standard deviation sLp and reproducibility standard deviation sR using: If this happens, the results of the precision experiment willwill be decreased and estimates of the betweenbe distorted: A design for a heterogeneous material It should be remembered that 572-5 object of choosing the materials for the split-level design is to provide the sio with samples that they do not expect to be identical.
Laboratory 6 obviously achieved a much worse repeatability than Laboratory 9 in this experiment, so that the assumption oso they achieve similar repeatability does not appear to be true in this instance. Table 17 gives the results of the calculations for the other levels. Methods for determination of particle size distribution.
The number of replicates, n in IS0may be taken to be the number of split-levels in a split-level iwo.
Royal Society of Chemistry, London. The approach that is used in the examples that follow is to use izo iterative method to find an approximate solution, then solve equation 68 to find the exact solution.
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.
To assess the uncertainty of the estimate of the bias of the measurement method in a split-level experiment, calculate the quantity Ieo as defined by equation 13 of IS0 The statistician, in this situation, has to decide between: 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, 57225-5. C informative Derivation of equations used for robust analysis If a laboratory is lso generally worse repeatability than the others, then it will show up as having an unusually large number of large h statistics in the graph derived from the cell differences.
The ISO Accuracy of Measurement Methods and Results Package provides the general principles necessary to accurately assess measurement methods, results, applications and practical estimations.
BS ISO 5725-5:1998
Applying Algorithm S using iteration gives the results shown in this table. The estimate of the between-laboratorystandard deviation is thus, from equation 72 in 6. If there are empty cells in table 3,p is now the number of cells in column j of table 3 containing data and the summation is performed over non-empty cells.
It is common to find this sort of pattern when plotting the data from a split-level design as in figure 1. Methods for determination of soundness. Using equation 78 in 6.
Use in practice of accuracy values – – Parts 1 to 6 of IS0 together cancel and replace IS0which has been extended to cover trueness in 55725-5 to precision and intermediate precision conditions in addition to repeatability conditions and reproducibilityconditions. With heterogeneous materials this may not be possible, so that the use of the basic method then gives estimates of the reproducibility standard deviation that are inflated by the isp between the samples.
This part of IS0 should be read in conjunction with IS0 because the underlying definitions and general principles are given there.
Such graphs can help identify those laboratories that have the largest biases relative to the other laboratories. 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.