DIN ISO 5725-2:2002-12, Genauigkeit (Richtigkeit und Präzision) von Messverfahren und Messergebnissen_- Teil_2: Grundlegende Methode für Ermittlung der Wiederhol- und Vergleichpräzision eines vereinheitlichten Messverfahrens (ISO_5725-2:1994 einschließlich Technisches Korrigendum_1:2002)

2002 ◽  
Keyword(s):  
Iso 5725

Introduction to Statistical Methods for Outlier Detection and Sample Homogeneity Assessment of Reference Materials and Proficiency Test Items

2021 ◽  
Author(s):  
Yi-Ting Chen ◽  
Keyword(s):  
Data Analysis ◽  
Outlier Detection ◽  
Reference Materials ◽  
Proficiency Test ◽  
Test Items ◽  
Homogeneity Assessment ◽  
Iso 13528 ◽  
Scope Of Application ◽  
Iso 5725 ◽  
Sample Homogeneity

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.

scholarly journals Methodical issues of the monitoring for ammonium in indoors air

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 ◽  
...  
Keyword(s):  
Indoor Air ◽  
Standard Method ◽  
Field Tests ◽  
Air Sampling ◽  
State Standards ◽  
Comparative Assessment ◽  
Sampling Time ◽  
Short Term ◽  
Material Costs ◽  
Iso 5725

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.

Experimental Designs for Interlaboratory Precision Experiments: Comparison of ISO 5725 with Draft NEN 6303

1989 ◽  
Vol 72 (1) ◽  
pp. 34-37 ◽  
Author(s):  
J Zaalberg
Keyword(s):  
Standard Deviation ◽  
Edible Oils ◽  
Collaborative Study ◽  
Experimental Designs ◽  
Interlaboratory Experiments ◽  
Interlaboratory Studies ◽  
Repeatability Standard Deviation ◽  
Level Design ◽  
Iso 5725

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.

Method validation by collaborative trial for the quantification of binary mixtures containing polyamide and a novel polypropylene/polyamide bicomponent fibre

2011 ◽  
Vol 81 (20) ◽  
pp. 2160-2167 ◽  
Author(s):  
Paola Piccinini ◽  
Marilena Trantallidi ◽  
Rafael Alvarez-Sarandes ◽  
Maria de Sertorio
Keyword(s):  
Binary Mixtures ◽  
Selective Dissolution ◽  
The Novel ◽  
Collaborative Trial ◽  
Scope Of Application ◽  
Fit For Purpose ◽  
Repeatability And Reproducibility ◽  
Iso 5725 ◽  
Reproducibility Limit ◽  
Accurate Quantification

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.

scholarly journals Reproducibility of three-dimensional landmarking and Frankfort horizontal plane construction: a comparison of conventional and novel landmarks in presurgical computed tomography scans

2021 ◽  
Author(s):  
Gauthier Dot ◽  
Frederic Rafflenbeul ◽  
Adeline Kerbrat ◽  
Philippe Rouch ◽  
Laurent Gajny ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Ct Scan ◽  
Three Dimensional ◽  
Computed Tomography Scans ◽  
Repeatability And Reproducibility ◽  
Frankfort Horizontal Plane ◽  
Cephalometric Measurements ◽  
Iso 5725 ◽  
Overall Reliability ◽  
3D Landmarks

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.

scholarly journals Data inter-comparisons in the context of the knowledge-gaining process: an overview

ACTA IMEKO ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 73 ◽  
Author(s):  
Franco Pavese ◽  
Abderafi Charki
Keyword(s):  
Design Of Experiment ◽  
Confidence Level ◽  
Mutual Recognition ◽  
Action Plan ◽  
Experimental Measurements ◽  
Testing Laboratories ◽  
Mutual Recognition Arrangement ◽  
Iso 13528 ◽  
Iso 5725 ◽  
Working Method

<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.

scholarly journals Selección de un método de aprendizaje automático para clasificar patrones biomarcadores de lesiones precancerosas de las cuerdas vocales

2020 ◽  
pp. 1-7
Author(s):  
Xóchitl Siordia-Vásquez ◽  
Luz Yazmin Villagrán-Villegas ◽  
Miguel Patiño-Ortiz ◽  
Miguel Ángel Rojas-Hernández
Keyword(s):  
Decision Tree ◽  
Precancerous Lesions ◽  
Roc Curves ◽  
World Health ◽  
Vocal Cords ◽  
Biomarker Pattern ◽  
Cord Injury ◽  
Health Organization ◽  
Confusion Matrices ◽  
Iso 5725

The National Survey on Drug, Alcohol and Tobacco, 2016-2017, notes that 15.6 million Mexicans are active smokers and, by 2030, expect the death of 8 million cancers of the larynx or lung. Therefore, the World Health Organization (WHO) recommends detecting precancerous lesions of the larynx. This is possible, as they are characterized by a biomarker pattern manifested by the alteration of the biomechanical interpretation of the vocal cords, regardless of the sex and age of the smoker. The goal of this article is to evaluate three machine learning methods: neural networks, Gaussian networks, and decision tree to determine the method that best solves the problem of detecting patterns of precancerous vocal cord injury biomarkers. It uses the WEKA tool and a knowledge bank, endorsed by NOM-012-SSA3-2012, with 250 patterns, and provided by the Luis Guillermo Ibarra National Institute of Rehabilitation, Ibarra. The performance of the methods was compared by ROC curves and confusion matrices, under the criteria established by ISO-5725. The decision tree the method that best responds to the detection of patterns of biomarkers of precancerous lesions of the vocal cords.

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