DIN ISO 5725-2:2020-10, Genauigkeit (Richtigkeit und Präzision) von Messverfahren und Messergebnissen_- Teil_2: Grundlegende Methode für die Ermittlung der Wiederhol- und Vergleichpräzision eines vereinheitlichten Messverfahrens (ISO_5725-2:2019); Text Deutsch und Englisch

2020 ◽  
Keyword(s):  
2021 ◽  
Author(s):  
Yi-Ting Chen ◽  

Due to the homogeneity of the product or sample, it will affect whether it meets the scope of application and purpose. For example, the reference materials(RM) produced by the reference material producer(RMP), and the proficiency test items selected by the proficiency testing provider(PTP), in order to ensure the reference materials or proficiency test items have consistent characteristics or comparability, they should be proved to have certain homogeneity. However, before performing homogeneity assessment, it is necessary to measure the characteristic parameters of the reference materials or proficiency test items to obtain a sufficient number of measured values for data analysis, but there may be outliers in the measured values that may affect data analysis and interpretation of the results. Therefore, this article will refer to ASTM E178-16a:2016[1], ISO 5725-2:1994[2], ISO 13528:2015[3], etc., to introduce several outlier detection and homogeneity assessment methods, supplemented by case studies. Finally, this article will remind the precautions for the use of the method, so that readers can choose the appropriate method for use in the actual analysis.


2019 ◽  
Vol 95 (10) ◽  
pp. 917-922 ◽  
Author(s):  
I. Sh. Iakubova ◽  
Yu. V. Dadaly ◽  
A. V. Mel’Tser ◽  
Lilia A. Alikbayeva ◽  
A. Yu. Zhirnov ◽  
...  

Introduction. To perform mass studies of the indoors air environment of the ammonium content the actual issues are the shortening of the sampling time and material costs for their implementation, reduction of adverse effects of ammonium with keeping of the objectivity of results. Aim. The elaboration of the method of short-term air sampling for indoors ammonium and comparative assessment ofdifferent methods of sampling in the course of modeling and field tests. Materials and Methods. Air sampling for ammonium was carried out according to the developed program and standard method, under the average daily 4-fold taking according to State Standards (GOST) 17.2.3.01-86 andRD 52.04.186-89. The evaluation of the significance of deviations of analysis results was carried out in accordance with GOST R ISO 5725-6-2002 and Recommendations of the Interstate Standardization RMG - 61-2003. Results. There were executed model and field tests of air sampling for ammonium according to the standard method and the program of short-term sampling. There were obtained significantly comparable results of ammonium content in the indoor air in the course of model and field tests. Conclusions. Sampling according to the developed program has a number of advantages, including: the shortening of sampling time, material costs, increasing in productivity in the analysis of indoor airfor the ammonium content. The execution oftest sampling according to the developed program allows to reduce the time of ammonium exposure to personnel carrying out the test sampling.


1989 ◽  
Vol 72 (1) ◽  
pp. 34-37 ◽  
Author(s):  
J Zaalberg

Abstract To determine the precision of standardized analytical methods, interlaboratory experiments are carried out in which several laboratories analyze identical samples from well homogenized batches of material. From the test results, estimates of the standard deviations under repeatability as well as under reproducibility conditions are calculated. In the present work, the experimental designs recommended in the International Standard ISO 5725 have been compared with a design proposed in the draft Netherlands Standard NEN 6303. This has been done by comparing their mathematical models as well as by applying them to the results of a recent collaborative study on the determination of heavy metals in edible oils and fats. The reproducibility standard deviation is estimated equally well with both Standards, but it appeared that the designs given in ISO 5725 can lead to serious underestimation (uniform-level design) or overestimation (split-level design) of the repeatability standard deviation. By using the design proposed in NEN 6303, these biases can be avoided. Hence, it is recommended that interlaboratory studies be organized according to the design of NEN 6303.


2011 ◽  
Vol 81 (20) ◽  
pp. 2160-2167 ◽  
Author(s):  
Paola Piccinini ◽  
Marilena Trantallidi ◽  
Rafael Alvarez-Sarandes ◽  
Maria de Sertorio

A method for the quantification of a novel polypropylene/polyamide bicomponent fibre in binary mixtures with polyamide was subjected to validation by collaborative trial. Considering the probable acceptance of the novel fibre in Europe, this method would allow market surveillance and antifraud controls needed for consumer protection. The aim of the study was to extend the scope of application of method 11 of Directive 96/73/EC. The method foresaw selective dissolution of the polyamide component using 75% m/m sulfuric acid at room temperature for 1 h. In order to ensure accurate quantification of the blends, two additional rinsings of the residue with the reagent used for the dissolution had to be included in the washing procedure of method 11. Following ISO 5725, a balanced uniform level test was performed, with the participation of seventeen European laboratories, on loop twisted carpet samples of three levels of concentration. The trueness was evaluated considering, as reference, data values obtained from manual separation. The bias varied from 0.06 to 0.49%. Repeatability and reproducibility limits were in the range 0.70–1.04% and 0.97–1.87%, respectively. In agreement with the members of the European Network of National Experts on Textile Labelling, the optimized method was judged fit-for-purpose and the reproducibility limit was established at 2%. Based on this study, the novel fibre can be inserted in the scope of application of method 11 as the insoluble component ( d factor 1.005) and polyamide as the soluble one, provided that modifications are adopted.


2021 ◽  
Author(s):  
Gauthier Dot ◽  
Frederic Rafflenbeul ◽  
Adeline Kerbrat ◽  
Philippe Rouch ◽  
Laurent Gajny ◽  
...  

Objectives To assess manual landmarking repeatability and reproducibility (R&R) of a set of three-dimensional (3D) landmarks and to evaluate R&R of vertical cephalometric measurements using two Frankfort Horizontal (FH) planes as references for horizontal 3D imaging reorientation. Methods Thirty-three landmarks, divided into "conventional", "foraminal" and "dental", were manually located twice by 3 experienced operators on 20 computed tomography (CT) scans of orthognathic surgery patients. R&R of the landmark localization were computed according to the ISO 5725 standard. These landmarks were then used to construct 2 FH planes: a conventional FH plane (orbitale left, porion right and left) and a newly proposed FH plane (midinternal acoustic foramen, orbitale right and left). R&R of vertical cephalometric measurements were computed using these 2 FH planes as horizontal references for CT reorientation. Results Landmarks showing a 95% confidence interval (CI) of repeatability and/or reproducibility > 2mm were found exclusively in the "conventional" landmarks group. Vertical measurements showed excellent R&R (95% CI < 1mm) with either FH plane as horizontal reference. However, the 2 FH planes were not found to be parallel (absolute angular difference of 2.41°, SD 1.27°). The average time needed to landmark one CT scan was 14 ± 3 minutes. Conclusions The "dental" and "foraminal" landmarks tended to be more reliable than the "conventional" landmarks. Despite the poor overall reliability of the landmarks orbitale and porion, the construction of the conventional FH plane using 3 landmarks provided a reliable horizontal reference for 3D craniofacial CT scan reorientation.


ACTA IMEKO ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 73 ◽  
Author(s):  
Franco Pavese ◽  
Abderafi Charki

<p>This paper deals with the principle of data inter-comparisons, the object of which is to increase knowledge continuously with respect to time. Although the principle is as such nothing new to metrology and testing laboratories, which carry out experimental measurements, a degree of clarification is nonetheless called for in view of the numerous questions that arise concerning ways of implementing and utilizing it to improve knowledge capitalization.</p><p>The acquisition of knowledge relative to any measurand involves a series of steps: studying the state of knowledge of the measurand, choosing a working method (typically, by establishing a design of experiment), obtaining the measurements, and analyzing them. Following this, an action plan is established in order to reduce (or if possible avoid) weaknesses or over sensitivity.</p>Comparisons are already conducted using various approaches within a laboratory. It is therefore important to understand that to assess the accuracy of a method and validate it, it is necessary to compare the results obtained by several laboratories for a given method and measurand with the correct type of inter-comparison. It is this comparison between several laboratories that, when using different methods, produces the most up to date knowledge with the highest confidence level. This paper goes over the steps that allow developing knowledge, presenting the aims and characteristics of the various inter-laboratory comparison methods, notably referring to the tools established by documents such as the BIPM MRA (the Mutual Recognition Arrangement), the ISO 5725 and the ISO 13528.


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