Accreditation and Quality Assurance最新文献_第2页

Measurement uncertainty in testing of biologicals in national control laboratories for ISO/IEC 17025: practical approaches ISO/IEC 17025 国家控制实验室生物制品检测中的测量不确定性：实用方法

IF 0.8 4区工程技术

Accreditation and Quality Assurance Pub Date : 2024-04-14 DOI: 10.1007/s00769-024-01589-8

Shalini Tewari, Niharika Trivedi, Sanchi Goel, Rashmi Shrivastava, Sudha V. Gopinath, Ayushi Khurana, Anupkumar R. Anvikar

引用次数: 0

The role of measurement uncertainty in the validation of a measurement procedure 测量不确定性在验证测量程序中的作用

IF 0.8 4区工程技术

Accreditation and Quality Assurance Pub Date : 2024-04-13 DOI: 10.1007/s00769-024-01593-y

Fernando C. Raposo, Michael H. Ramsey

引用次数: 0

Comparison of continuous flow analysis and ion chromatography for determinations of nitrate, nitrite and phosphate ions in seawater and development of related seawater certified reference materials 比较连续流动分析法和离子色谱法测定海水中的硝酸盐、亚硝酸盐和磷酸盐离子，并开发相关的海水认证参考材料

IF 0.8 4区工程技术

Accreditation and Quality Assurance Pub Date : 2024-04-10 DOI: 10.1007/s00769-024-01586-x

Chikako Cheong, Toshihiro Suzuki, Tsutomu Miura, Akiharu Hioki

引用次数: 0

Quality control charts for short or long runs without a training phase. Part 1. Performances in state of control and in the presence of outliers 无训练阶段短跑或长跑的质量控制图。第 1 部分。控制状态下和出现异常值时的性能

IF 0.8 4区工程技术

Accreditation and Quality Assurance Pub Date : 2024-03-27 DOI: 10.1007/s00769-024-01584-z

Manuel Alvarez-Prieto, Ricardo S. Páez-Montero

{"title":"Quality control charts for short or long runs without a training phase. Part 1. Performances in state of control and in the presence of outliers","authors":"Manuel Alvarez-Prieto, Ricardo S. Páez-Montero","doi":"10.1007/s00769-024-01584-z","DOIUrl":"10.1007/s00769-024-01584-z","url":null,"abstract":"<div><p>Sometimes analytical laboratories receive requests with a small number of determinations and/or a small number of samples, or outside the typical scope of analytical services. As a result, they may not have historical data on the performance of analytical processes and/or appropriate reference materials. Under these conditions it is difficult or uneconomical to use traditional or classic quality control charts. This is the so-called start-up problem of these charts. The Q charts seem appropriate charts under these conditions because they do not need any prior training or study phase. The fundamentals and the algebraic expressions of Q charts for the mean (four cases) and for the variance (two cases) are offered. This experimental study of Q charts for individual measurements was done with data from quality control for the evaluation of mass fraction of Ni and Al<sub>2</sub>O<sub>3</sub> in a laterite CRM by ICP-OES. The performance of these Q charts is discussed where the analytical process is in the state of statistical control and in the presence of outliers at the start-up. In the first situation performance of Q charts are quite satisfactory and they behave properly. When outliers are collected at the beginning, the deformation of some charts is evident or the charts become useless. Severe outliers will corrupt the parameter estimates and the subsequent plotted points, or the charts will become insensitive and useless. The practitioner should take extreme care to assure that the initial values are obtained in the state of statistical control to have adequate sensitivity to detect parameter shifts.</p></div>","PeriodicalId":454,"journal":{"name":"Accreditation and Quality Assurance","volume":"29 3","pages":"231 - 242"},"PeriodicalIF":0.8,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140374927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improved coverage factors for expanded measurement uncertainty calculated from two estimated variance components 根据两个估计方差分量计算的扩大测量不确定性的改进覆盖因子

IF 0.8 4区工程技术

Accreditation and Quality Assurance Pub Date : 2024-03-27 DOI: 10.1007/s00769-024-01579-w

Peter D. Rostron, Tom Fearn, Michael H. Ramsey

{"title":"Improved coverage factors for expanded measurement uncertainty calculated from two estimated variance components","authors":"Peter D. Rostron, Tom Fearn, Michael H. Ramsey","doi":"10.1007/s00769-024-01579-w","DOIUrl":"10.1007/s00769-024-01579-w","url":null,"abstract":"<div><p>Measurement uncertainty (MU) arising at different stages of a measurement process can be estimated using analysis of variance (ANOVA) on replicated measurements. It is common practice to derive an expanded MU by multiplying the resulting standard deviation by a coverage factor <i>k.</i> This coverage factor then defines an interval around a measurement value within which the value of the measurand, or true value, is asserted to lie for a desired confidence level (e.g. 95 %). A value of <i>k</i> = 2 is often used to obtain approximate 95 % coverage, although <i>k</i> = 2 will be an underestimate when the standard deviation is estimated from a limited amount of data. An alternative is to use Student’s <i>t-</i>distribution to provide a value for <i>k</i>, but this requires an exact or approximate degrees of freedom (df). This paper explores two different methods of deriving an appropriate <i>k</i> in the case when two variances from an ANOVA (classical or robust) need to be combined to estimate the measurement variance. Simulations show that both methods using the modified coverage factor generally produce a confidence interval much closer to the desired level (e.g. 95 %) when the data are approximately normally distributed. When these confidence intervals do deviate from 95 %, they are consistently conservative (i.e. reported coverage is higher than the nominal 95 %). When outlying values are included at the level of the larger variance component, in some cases the method used for robust ANOVA produces confidence intervals that are very conservative.</p></div>","PeriodicalId":454,"journal":{"name":"Accreditation and Quality Assurance","volume":"29 3","pages":"225 - 230"},"PeriodicalIF":0.8,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00769-024-01579-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140377570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Information combination and transformation: a paradox and its resolution 信息组合与转换：一个悖论及其解决方案

IF 0.8 4区工程技术

Accreditation and Quality Assurance Pub Date : 2024-03-23 DOI: 10.1007/s00769-024-01578-x

Hening Huang

引用次数: 0

A practical two-step procedure for taking into account all available information (prior and current) about influence quantities in measurement uncertainty analysis 在测量不确定性分析中考虑有关影响量的所有可用信息（先验信息和当前信息）的实用两步程序

IF 0.8 4区工程技术

Accreditation and Quality Assurance Pub Date : 2024-03-23 DOI: 10.1007/s00769-024-01583-0

Hening Huang

{"title":"A practical two-step procedure for taking into account all available information (prior and current) about influence quantities in measurement uncertainty analysis","authors":"Hening Huang","doi":"10.1007/s00769-024-01583-0","DOIUrl":"10.1007/s00769-024-01583-0","url":null,"abstract":"<div><p>This paper considers the problem of computing the combined standard uncertainty of an indirect measurement, in which the measurand is related to multiple influence quantities through a measurement model. In practice, there may be prior information or current information, or both, about the influence quantities. We propose a practical two-step procedure for taking into account all available information (prior and current) about influence quantities in measurement uncertainty analysis. The first step is to combine prior and current information to form the merged information for each influence quantity based on the weighted average method or the law of combination of distributions. The second step deals with the propagation of the merged information to calculate the combined standard uncertainty using the law of propagation of uncertainty or the principle of propagation of distributions. The proposed two-step procedure is based entirely on frequentist statistics. A case study on the calibration of a test weight (mass calibration) is presented to demonstrate the effectiveness of the proposed two-step procedure and compare it with a subjective Bayesian approach.</p></div>","PeriodicalId":454,"journal":{"name":"Accreditation and Quality Assurance","volume":"29 3","pages":"215 - 223"},"PeriodicalIF":0.8,"publicationDate":"2024-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140210816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Paradox? What paradox? 悖论？什么悖论？

IF 0.8 4区工程技术

Accreditation and Quality Assurance Pub Date : 2024-03-23 DOI: 10.1007/s00769-024-01577-y

R. Willink

引用次数: 0

Target uncertainty: a critical review 目标的不确定性：严格审查

IF 0.8 4区工程技术

Accreditation and Quality Assurance Pub Date : 2024-03-19 DOI: 10.1007/s00769-024-01585-y

Fernando C. Raposo, Michael H. Ramsey

引用次数: 0

The comparison of flow rate calibration methods for high-performance liquid chromatography (HPLC) pump 高效液相色谱泵流速校准方法的比较

IF 0.8 4区工程技术

Accreditation and Quality Assurance Pub Date : 2024-03-15 DOI: 10.1007/s00769-024-01580-3

Prangtip Uthaiwat, Theera Leeudomwong, Tassanai Sanponpute

{"title":"The comparison of flow rate calibration methods for high-performance liquid chromatography (HPLC) pump","authors":"Prangtip Uthaiwat, Theera Leeudomwong, Tassanai Sanponpute","doi":"10.1007/s00769-024-01580-3","DOIUrl":"10.1007/s00769-024-01580-3","url":null,"abstract":"<div><p>High-performance liquid chromatography (HPLC) pump has a main function to deliver a mobile phase which needs accuracy and stable flow rate. Recently, the reference of General European OMCL Network 2005: Qualification of Equipment Annex 1 qualification of liquid chromatography equipment presents three flow rate calibration methods that have been used to calibrate the HPLC pump performance such as using standard flow meter, gravimetric method, and volumetric method. In this reference, the calibration methods have not been clearly described. Therefore, this study aimed to investigate and compare the flow rate calibration by the using standard flow meter, gravimetric method, and volumetric method. The flow rate was calibrated at 0.5 and 5 mL/min with three replications. The stability between days of each method was observed for three days. The calibration procedure, traceability chart, and uncertainty budget of each method had been described. The flow rate results were analyzed by using the <i>E</i><sub><i>n</i></sub> ratio. The results showed that the stability of all methods had no statistically significant difference between days when compared to the first day itself. The average measurement flow rates by using standard flow meter, gravimetric method, and volumetric method at 0.5 mL/min were 0.4908, 0.4992, and 0.5012 mL/min, respectively, and at 5 mL/min, they were 4.8346, 4.8272, and 4.8394 mL/min, respectively. These flow rates showed consistent results between each other as confirmed with the <i>E</i><sub><i>n</i></sub> ratio ≤ 1. The precision of the three methods was 0.01 to 0.08 %RSD. This study concluded that the flow rate results of three calibration methods had been consistent with each other. All methods had a good stability and precision for the flow rate calibration of the HPLC pump.</p></div>","PeriodicalId":454,"journal":{"name":"Accreditation and Quality Assurance","volume":"29 3","pages":"205 - 214"},"PeriodicalIF":0.8,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140240497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0