The MCCB Electrical Clearance and Creepage Distance Measurement Uncertainty Evaluation

2015 ◽  
Vol 742 ◽  
pp. 86-89
Author(s):  
Jing Zhang ◽  
Feng Wang ◽  
Jun Gang Zhou ◽  
Ming Long Hu
Keyword(s):  
Measurement Uncertainty ◽  
Circuit Breaker ◽  
Distance Measurement ◽  
Safety Performance ◽  
Electrical Safety ◽  
Uncertainty Sources ◽  
Uncertainty Calculation ◽  
Measurement Results ◽  
The Mathematical Model ◽  
Measurement Uncertainty Evaluation

The electrical clearance and creepage distance are two key parameters for the design of MCCB (molded case circuit breaker, MCCB), which directly influences the electrical safety performance of MCCB. In this paper, the electrical clearance and creepage distance measurement uncertainty were evaluated through the uncertainty sources analysis, the mathematical model establishment and the components uncertainty calculation, to ensure the accuracy of the measurement results.

Uncertainty Calculation of Roundness by Automatic Differentiation

2010 ◽  
Vol 437 ◽  
pp. 217-221
Author(s):  
Jia Chun Lin ◽  
Michael Paul Krystek ◽  
Zhao Yao Shi
Keyword(s):  
Measurement Uncertainty ◽  
Automatic Differentiation ◽  
Uncertainty In Measurement ◽  
Uncertainty Calculation ◽  
Measurement Results ◽  
Coordinate Metrology ◽  
Data Points ◽  
Roundness Deviation ◽  
Expression Of Uncertainty ◽  
Roundness Measurement

According to the Guide to the Expression of Uncertainty in Measurement (GUM), all measurement results must have a stated uncertainty associated to them. But in most cases of roundness measurement either no uncertainty value is given, or the calculation is not based on the model of the respective association criterion for the geometrical feature, because no suitable measurement uncertainty calculation procedure does exist. For the case of roundness measurement in coordinate metrology, this paper will suggest algorithms for the calculation of the measurement uncertainty of the roundness deviation based on the two mainly used association criteria LSC and MZC. The calculation of the sensitivity coefficients for the uncertainty calculation can be done by automatic differentiation, in order to avoid introducing additional errors by the traditional difference quotient approximations. The proposed methods are exact and need as input data only the measured co-ordinates of the data points and their associated uncertainties.

Uncertainty Analysis of Helical Deviation Measurements

2010 ◽  
Vol 437 ◽  
pp. 212-216 ◽  
Author(s):  
Zhao Yao Shi ◽  
Jia Chun Lin ◽  
Michael Paul Krystek
Keyword(s):  
Measurement Uncertainty ◽  
Measurement Errors ◽  
National Standards ◽  
Calculation Procedure ◽  
Uncertainty In Measurement ◽  
Uncertainty Calculation ◽  
Measurement Results ◽  
Polar Coordinate ◽  
Expression Of Uncertainty ◽  
Dynamical Measurement

The helix is a complex geometrical element. During the process of a dynamical measurement of the helical deviations, many factors, including the machine and the environment, lead to measurement errors. Although ISO as well as national standards stipulate the tolerances and assessment methods for helical deviations, these standards contribute little to the uncertainty calculations concerning such measurements. According to the Guide to the Expression of Uncertainty in Measurement (GUM), all measurement results must have a stated uncertainty associated to them. But in most cases of helical deviation measurements, no uncertainty value is given, simply because no measurement uncertainty calculation procedure exists. For the case of helical deviation measurements on a Computer Numeric Control (CNC) polar coordinate machine, this paper analyses in detail all kinds of factors contributing to the measurement uncertainty, and gives the calculation procedure of the measurement uncertainty of helical deviation. As an example, the calculation of the measurement uncertainty of the helical deviations of a worm is presented.

scholarly journals Two approaches for measurement uncertainty estimation: which role for bias? Complete blood count experience

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hatice Bozkurt Yavuz ◽  
Süleyman Caner Karahan ◽  
Hüseyin Yaman ◽  
Asım Örem ◽  
Yüksel Aliyazıcıoğlu
Keyword(s):  
Measurement Uncertainty ◽  
Blood Count ◽  
Concentration Level ◽  
Complete Blood Count ◽  
Performance Expectations ◽  
Uncertainty Calculation ◽  
Measurement Results ◽  
Measurement Uncertainty Estimation ◽  
Quality Control Data ◽  
Different Levels

Abstract Objectives Measurement uncertainty is described as a magnitude indicates the distribution of the measurement results. AACB Guideline suggests that bias should not be included in the uncertainty calculation contrary to Nordtest Guideline. The aim of the study is to calculate the uncertainty values of certain complete blood count (CBC) parameters and evaluate the contribution of bias. Methods This retrospective study was performed with the quality control data of January–December 2017 of two different CBC autoanalyser models (Beckman Coulter LH780 and DXH800). Measurement uncertainties were calculated according to AACB and Nordtest Guidelines. Imprecision, i.e. measurement uncertainty, varies with concentration. Imprecision values of user manuals, as performance characteristics of autoanalyzers, were used for assessment. Results User manuals imprecision values of different levels of platelets are between 3.3 and 14%. As the concentrations of platelets decrease, imprecision is observed to increase. This is expected to be parallel with measurement uncertainty. Contrary to user manuals, uncertainty values of AACB found to be so close to each other (between 3.41% and 4.80%), regardless of concentration level. However Nordtest guideline is more compatible with user manuals (between 6.97% and 15.35%). Conclusions When evaluated with the performance expectations, bias should be used in measurement uncertainty. Calculation of uncertainty for different concentration level is also important. Amaç Ölçüm belirsizliği, bir büyüklük olarak ölçüm sonuçlarının dağılımını ifade eder. AACB Kılavuzu, Nordtest Kılavuzunun aksine, biasın belirsizlik hesaplamasına dahil edilmesini önermemektedir. Çalışmanın amacı, belirli tam kan sayımı (CBC) parametrelerinin belirsizlik değerlerini hesaplamak ve biasın katkısını değerlendirmektir. Gereç ve Yöntemler Bu retrospektif çalışma, iki farklı CBC otoanalizör modelinin (Beckman Coulter LH780 ve DXH800) Ocak-Aralık 2017 kalite kontrol verileriyle gerçekleştirildi. Ölçüm belirsizlikleri AACB ve Nordtest Kılavuzlarına göre hesaplandı. İmpresizyon, dolayısıyla ölçüm belirsizliği, konsantrasyona göre değişir. Belirsizlik sonuçlarını değerlendirmede otoanalizörlerin kullanım kılavuzlarında yer alan impresizyona dayalı performans özellikleri kullanılmıştır. Bulgular Farklı trombosit düzeylerinin kullanım kılavuzlarındaki impresizyon değerleri %3.3-%14 arasındadır. Trombosit konsantrasyonu düştükçe impresizyon artar. Bunun ölçüm belirsizliği ile paralel olması beklenir. Kullanım kılavuzlarının aksine, AACB’ye göre hesaplanan belirsizlik değerleri, konsantrasyon seviyesinden bağımsız olarak birbirine çok yakın (%3.41–%4.80 arasında) bulundu. Bununla birlikte, Nordtest kılavuzunun sonuçları,otoanalizörlerin kullanım kılavuzları ile daha uyumlu bulundu (%6.97–%15.35 arasında). Sonuç Performans beklentileri ile değerlendirildiğinde, ölçüm belirsizliğinde bias kullanılmalıdır. Farklı konsantrasyon seviyeleri için belirsizliğin ayrı ayrı hesaplanması da önemlidir.

scholarly journals Analysis of measurement uncertainty sources in the casting process

2021 ◽  
Vol 9 (2) ◽  
pp. 1-4
Author(s):  
Lisiane Trevisan ◽  
Vinicius de Freitas Paz ◽  
Daniel Antonio Kapper Fabricio
Keyword(s):  
Decision Making ◽  
Literature Review ◽  
Measurement Uncertainty ◽  
Casting Process ◽  
World Market ◽  
Uncertainty Of Measurement ◽  
Uncertainty Sources ◽  
Uncertainty Calculation ◽  
The World ◽  
Productive Process

The concepts used in metrology are increasingly part of the productive process of metallurgical companies, considering the globalization of the world market. The interpretation of metrological concepts and their application in decision-making is still a challenge for the industry, especially for the measurement uncertainty calculation. Industries in the casting area are in great need of skilled labor both in relation to the productive process and engineering, as well as in metrology, highlighting the interdisciplinary of the concepts studied in the technical or baccalaureate courses. Therefore, the main objective of this work is to perform a brief literature review of publications made using the value of uncertainty of measurement within the production process of foundries. The results show that there is a potential research in the field, to which it relates the values of measurement uncertainty and fused components.

scholarly journals Measurement Uncertainty Evaluation Method Considering Correlation and its Application to Precision Centrifuge

2014 ◽  
Vol 14 (6) ◽  
pp. 308-316 ◽  
Author(s):  
Mingxiang Ling ◽  
Huimin Li ◽  
Qisheng Li
Keyword(s):  
Measurement Uncertainty ◽  
Evaluation Method ◽  
Correlation Coefficients ◽  
Uncertainty Evaluation ◽  
Uncertainty In Measurement ◽  
Uncertainty Sources ◽  
The Monte Carlo Method ◽  
Marginal Probability Distribution ◽  
Non Gaussian ◽  
Measurement Uncertainty Evaluation

Abstract Measurement uncertainty evaluation based on the Monte Carlo method (MCM) with the assumption that all uncertainty sources are independent is common. For some measure problems, however, the correlation between input quantities is of great importance and even essential. The purpose of this paper is to provide an uncertainty evaluation method based on MCM that can handle correlated cases, especially for measurement in which uncertainty sources are correlated and submit to non-Gaussian distribution. In this method, a linear-nonlinear transformation technique was developed to generate correlated random variables sampling sequences with target prescribed marginal probability distribution and correlation coefficients. Measurement of the arm stretch of a precision centrifuge of 10-6 order was implemented by a high precision approach and associated uncertainty evaluation was carried out using the mentioned method and the method proposed in the Guide to the Expression of Uncertainty in Measurement (GUM). The obtained results were compared and discussed at last.

scholarly journals The Impact of Elongation on Change in Electrical Resistance of Electrically Conductive Yarns Woven into Fabric

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3390
Author(s):  
Željko Knezić ◽  
Željko Penava ◽  
Diana Šimić Penava ◽  
Dubravko Rogale
Keyword(s):  
Mathematical Model ◽  
Electrical Resistance ◽  
Electrically Conductive ◽  
Textile Materials ◽  
Measurement Results ◽  
Conductive Yarns ◽  
Yarn Count ◽  
As Relationship ◽  
The Impact ◽  
The Mathematical Model

Electrically conductive yarns (ECYs) are gaining increasing applications in woven textile materials, especially in woven sensors suitable for incorporation into clothing. In this paper, the effect of the yarn count of ECYs woven into fabric on values of electrical resistance is analyzed. We also observe how the direction of action of elongation force, considering the position of the woven ECY, effects the change in the electrical resistance of the electrically conductive fabric. The measurements were performed on nine different samples of fabric in a plain weave, into which were woven ECYs with three different yarn counts and three different directions. Relationship curves between values of elongation forces and elongation to break, as well as relationship curves between values of electrical resistance of fabrics with ECYs and elongation, were experimentally obtained. An analytical mathematical model was also established, and analysis was conducted, which determined the models of function of connection between force and elongation, and between electrical resistance and elongation. The connection between the measurement results and the mathematical model was confirmed. The connection between the mathematical model and the experimental results enables the design of ECY properties in woven materials, especially textile force and elongation sensors.

Estimation of uncertainty in olfactometry

2009 ◽  
Vol 59 (7) ◽  
pp. 1409-1413 ◽  
Author(s):  
T. Higuchi
Keyword(s):  
Measurement Uncertainty ◽  
Interlaboratory Comparison ◽  
Collaborative Study ◽  
Estimation Procedure ◽  
Measurement Model ◽  
Standard Uncertainty ◽  
Expanded Uncertainty ◽  
Collaborative Test ◽  
Measurement Results ◽  
Estimation Of Uncertainty

Estimation of uncertainty in odour measurement is essential to the interpretation of the measurement results. The fundamental procedure for the estimation of measurement uncertainty comprises the specification of the measurement process, expression of the measurement model and all influences, evaluation of the standard uncertainty of each component, calculation of the combined standard uncertainty, determination of a coverage factor, calculation of the expanded uncertainty and reporting. Collaborative study such as interlaboratory comparison of olfactometry yields performance indicators of the measurement method including repeatability and reproducibility. Therefore, the use of collaborative test results for measurement uncertainty estimation according to ISO/TS 21748 and ISO 20988 is effective and reasonable. Measurement uncertainty of the triangular odour bag method was estimated using interlaboratory comparison data from 2003 to 2007 on the basis of the simplest model of statistical analysis, and the expanded uncertainty of odour index ranged between 3.1 and 6.7. On the basis of the establishment of the estimation procedure for uncertainty, a coherent interpretation method for the measurement results will be proposed and more effective and practical quality control of olfactometry will be available.

Measurement uncertainty evaluation of conicity error inspected on CMM

2015 ◽  
Vol 29 (1) ◽  
pp. 212-218 ◽  
Author(s):  
Dongxia Wang ◽  
Aiguo Song ◽  
Xiulan Wen ◽  
Youxiong Xu ◽  
Guifang Qiao
Keyword(s):  
Measurement Uncertainty ◽  
Uncertainty Evaluation ◽  
Measurement Uncertainty Evaluation

scholarly journals Uncertainty of factor Z in gravimetric volume measurement

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 198
Author(s):  
Mar Lar Win
Keyword(s):  
Measurement Method ◽  
Volume Measurement ◽  
Liquid Volume ◽  
Combined Effects ◽  
Apparent Mass ◽  
Mass Measurements ◽  
Iso Standards ◽  
Uncertainty Calculation ◽  
Measurement Results

<p class="Abstract">In the gravimetric volume measurement method, the factor <em>Z</em> is generally used to facilitate an easy conversion from the apparent mass obtained using a balance to the liquid volume. The uncertainty of the measurement used for the liquid volume can be divided into two specific contributions: one from the components related to the mass measurements and one from those related to the mass-to-volume conversion. However, some ISO standards and calibration guides have suggested that the uncertainty due to the factor <em>Z</em> is generally neglected in the uncertainty calculation pertaining to gravimetric volume measurement. This paper describes the combined effects of the density of the water, the density of the reference weights, and the air buoyancy on the uncertainty of factor <em>Z</em> in terms of how they subsequently affect the uncertainty of the measurement results.</p>

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