scholarly journals Determination of probe non-linearity and error due to measurement position for direct measurement type of gauge block comparator and its measurement uncertainty

2021 ◽  
Vol 2145 (1) ◽  
pp. 012060
Author(s):  
A Pringkasemchai ◽  
J Wongsaroj ◽  
K Mongkolsuttirat
Keyword(s):  
Measurement Uncertainty ◽  
Direct Measurement ◽  
Comparative Method ◽  
Standard Uncertainty ◽  
Simple Linear Regression ◽  
Measuring Range ◽  
Gauge Block ◽  
Measurement Results ◽  
Accuracy Of Measurement

Abstract The non-linearity of probes is one of the important components in gauge block calibration by the mechanical comparative method of two gauges blocks at the same nominal length. However, an advanced method for gauge block calibration is a mechanical direct measurement method of two gauge blocks showing the greatest difference in nominal length of 25 mm. This method uses a special probe based on the interferential scanning principle to produce the signals to measure the displacement. In this paper, non-linearity and error due to measurement position were investigated as they related to the accuracy of measurement results. The differences in central length of pairs of standard gauge blocks made of steel were measured by optical interferometry with the measurement uncertainty (k=2) 23 nm. Length in the range of 5 μm to 25 mm was used in the experiment. Non-linearity of the probe was evaluated by the simple linear regression model. Various factors such as origin setting point, temperature, and vibration have been analysed. In the preliminary experiment, the non-linearity, position error, repeatability and retrace error over the measuring range 25 mm are 13 nm, -18 nm, 15 nm, and 10 nm respectively. The standard uncertainty of direct measurement type caused by non-linearity is 4 nm.

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.

scholarly journals INVESTIGATION OF MEASUREMENT ACCURACY IN DETERMINING THE MASS OF BULK MATERIALS

2020 ◽  
Vol 8 (2) ◽  
pp. 42-48
Author(s):  
Galina V. Simonova
Keyword(s):  
Bulk Density ◽  
Fractional Composition ◽  
Bulk Material ◽  
Indirect Measurement ◽  
Bulk Materials ◽  
Technological Processes ◽  
Measurement Results ◽  
Accuracy Of Measurement ◽  
Fractional Control

The article is devoted to the assessment the error in determining the mass of a sample bulk materials when using the values of their bulk density. Precisely the accuracy of measurement results is necessary in many fields of activity to ensure the efficiency and safety of technological processes, as well as improving product quality. The relevance of this work is associated with the assessment of the inevitable deviations of the bulk density the same material in a given volume as a result of an uncontrolled fractional composition of a sample of bulk material. As a consequence of these deviations, an error arises in determining the mass of a sample of a given volume, even if this volume is an uniquely determined quantity. The paper presents the results of studies of the influence of the fractional composition of bulk materials on the determination of their mass in the indirect measurement method. A significant effect of the fractional composition of bulk materials on the error of the indirect method for determining the mass of the sample was revealed. It is shown, that there is a need for fractional control of the composition of bulk materials in the development of control operations of technological processes, as well as restrictions on the use of bulk density with increased requirements for the accuracy of determining the mass of a sample.

scholarly journals Determination of measurement uncertainty as a necessary condition confirming the reliability of measurement results

Rail Vehicles ◽  
2019 ◽  
pp. 39-49
Author(s):  
Joanna Wojtukiewicz
Keyword(s):  
Measurement Uncertainty ◽  
Necessary Condition ◽  
Measurement Results ◽  
Reliability Of Measurement Results

W artykule zawarto najważniejsze zagadnienia związane z wyznaczaniem niepewności pomiaru oraz z przedstawianiem wiarygodnych wyników pomiarów. Przedstawiono m.in. najważniejsze pojęcia dotyczące niepewności pomiaru, wymagania normatywne, źródła, cel oraz metody wyznaczania niepewności pomiaru. Artykuł zawiera również odniesienie do czynności metrologicznych wykonywanych w Laboratorium Badań Pojazdów Szynowych w celu spełnienia przedstawionych wymagań.

Evaluation of Uncertainty Measurement with Intelligent Contact Type Interferometer

2013 ◽  
Vol 333-335 ◽  
pp. 348-352
Author(s):  
Jin Hai Li ◽  
Xing Long Wang ◽  
Suo Sheng Cao ◽  
Zhan Biao Song
Keyword(s):  
Mathematical Modeling ◽  
Measurement Uncertainty ◽  
Computer Technology ◽  
Measurement Method ◽  
Standard Uncertainty ◽  
Expanded Uncertainty ◽  
Comparative Measurement ◽  
Gauge Block ◽  
Contact Type ◽  
Uncertainty Measurement

An evaluation is conducted to the uncertainty measurement with contact type interferometer after intellectualized improvement. CMOS sensing photographing technology and computer technology are applied to the improvement of contact type interferometer. A mathematical modeling is established by taking pixel number as reading unit and gauge block length comparative measurement method as means. The purpose is to analyze the source of measurement uncertainty, estimate the standard uncertainty of input, evaluate and set forth the expanded uncertainty. The result of evaluation is superior to the level of measurement uncertainty before improvement.

scholarly journals Comparison tests for the determination of the viscosity values of reference liquids by capillary viscometers and stabinger viscometer SVM 3001

2018 ◽  
Vol 9 ◽  
pp. 7 ◽  
Author(s):  
Gokce Sevim Sariyerli ◽  
Orhan Sakarya ◽  
Umit Yuksel Akcadag
Keyword(s):  
Viscosity Measurement ◽  
National Standard ◽  
Measuring Range ◽  
Primary Level ◽  
Low Viscosity ◽  
Measurement Results ◽  
Accredited Laboratories ◽  
Primary Standards ◽  
Capillary Viscometers

The present study was realized for measuring viscosities of reference liquids using capillary viscometers and Stabinger viscometer SVM 3001 with viscosity interval between 1 mm2/s and 5000 mm2/s with temperatures from 20 °C to 80 °C. Based on our measurement with various liquids, we determine the viscosity values and compare both of the results. The aim of this study to evaluate the results of the primary level viscosity measurement system and stabinger viscometer and to compare the measurement results due to the providing traceability of Stabinger viscometer by TUBITAK UME. An increasing number of national metrology institutes and accredited laboratories provide viscometer calibration with reference liquids in a wide viscosity range. It is a common practice to use the viscosity of water as the metrological basic of viscometry. The national standard of viscosity provided by TUBITAK UME consists of a set of ubbelohde viscometers covering the measuring range of kinematic viscosities from about 0.5 mm2/s to 100 000 mm2/s. At the low viscosity, long − capillary viscometers are used as primary standards which are directly calibrated water.

scholarly journals Expanded uncertainty evaluation taking into account the correlation between estimates of input quantities

2021 ◽  
pp. 4-8
Author(s):  
Igor Zakharov ◽  
Pavel Neyezhmakov ◽  
Olesia Botsiura
Keyword(s):  
Measurement Uncertainty ◽  
Correlation Coefficient ◽  
Degrees Of Freedom ◽  
Reduction Method ◽  
Standard Uncertainty ◽  
Effective Number ◽  
Expanded Uncertainty ◽  
Wide Range ◽  
Measurement Results ◽  
Processing Of Measurement Results

An expression for estimating the combined standard uncertainty taking into account the observed correlation between the estimates of the two input quantities is given. The Welch – Satterthwaite formula given in the GUM is analyzed. It is shown that the number of degrees of freedom calculated using this formula will vary over a wide range when the value of the correlation coefficient changes, and in some cases it may take an unacceptable zero value. An expression for calculating the combined standard uncertainty by the reduction method is given. It is shown that the number of degrees of freedom in this method does not depend on the value of the correlation coefficient. A formula for calculating the effective number of degrees of freedom taking into account the observed correlation is proposed. The existing expression for calculating the kurtosis of the measurand is analyzed and an expression is proposed for calculating the kurtosis of the measurand in the presence of a correlation between the input quantities. An example of estimation of expanded uncertainty when measuring the coefficient of a pressure transducer using a calibrator is considered. Estimates of the distribution of the measurand, obtained using Monte Carlo simulation, showed that they are closest to the estimates obtained by the kurtosis method. The considered example showed that taking into account the correlation in the processing of measurement results makes it possible to reduce the expanded measurement uncertainty of the converter coefficient by 1.22–1.27 times. Keywords: measurement uncertainty; correlation; effective number of degrees of freedom; method of kurtosis

scholarly journals Estimation of the Measurement Uncertainty of the High-Performance Anion-Exchange Chromatographic Determination of Carbohydrates in Soluble (Instant) Coffee

2004 ◽  
Vol 87 (3) ◽  
pp. 647-656 ◽  
Author(s):  
Paul Stöber ◽  
Véronique Giller ◽  
Lionel Spack ◽  
Jacques Prodolliet
Keyword(s):  
Measurement Uncertainty ◽  
Anion Exchange ◽  
High Performance ◽  
Standard Uncertainty ◽  
Calibration Model ◽  
Linear Calibration ◽  
Total Uncertainty ◽  
Instant Coffee ◽  
Relative Standard

Abstract The measurement uncertainty of the determination of free and total carbohydrates in soluble (instant) coffee using high-performance anion exchange chromatography with pulsed amperometric detection according to AOAC Method 995.13 and ISO standard 11292 was calculated. This method is important with regard to monitoring several carbohydrate concentrations and is used to assess the authenticity of soluble coffee. We followed the recommendations of the ISO, Eurachem, and Valid Analytical Measurement (VAM) guides: individual uncertainty contributions u(x) were identified, quantified, and expressed as relative standard deviations related to each specific source u(x)/x or RSD(x). Eventually, they were combined to yield the standard uncertainty and the relative standard uncertainty of a given carbohydrate concentration, c, that is respectively u(c) and u(c)/c. As a result of our study, we could demonstrate that the overall repeatability of the carbohydrate determination in duplicate, RSD(r); the repeatability of the integration of the peak area of the carbohydrate standards, RSD(rarea(ST)); and the uncertainty of the linear calibration model used in our laboratory, RSD (linST), are the most significant contributions to the total uncertainty. The u(c)/c values thus determined differ for each carbohydrate and depend on their concentrations. The least standard uncertainties that can be achieved are about 2.5%. The question of trueness in the total carbohydrate assay (determination of monosaccharides obtained upon hydrolysis of coffee oligo- and polysaccharides) was addressed. For this purpose, we analyzed the data of 2 different collaborative trials in which our laboratory took part.

Evaluation of Measurement Uncertainty for the Determination of MgO in Magnesia Refractories by XRF

2018 ◽  
Vol 768 ◽  
pp. 36-40
Author(s):  
Qing Dan Yuan ◽  
Shi Hua Liu ◽  
Qian Nan Li ◽  
Wei Han
Keyword(s):  
Measurement Uncertainty ◽  
Mathematical Models ◽  
Magnesium Oxide ◽  
Oxide Content ◽  
Refractory Materials ◽  
Melting Method ◽  
X Ray ◽  
Measurement Results ◽  
Synthetic Standard

The method of X-ray fluorescence spectrometry (XRF) for the determination of MgO in magnesia refractories was introduced. The uncertainty of the MgO in refractory materials was analyzed by melting method of XRF. The measurement uncertainty was evaluated, and the related mathematical models was established. The uncertainty of synthetic standard was calculated by the evaluation of the uncertainty of each component standard. And eventually converted to the measurement results to expand the uncertainty. The effects of two melting methods on the uncertainty of magnesium oxide content were compared.

scholarly journals Calculation of Misjudgment Probability for Product Inspection Based on Measurement Uncertainty

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Xiao-huai Chen ◽  
Yin-bao Cheng ◽  
Han-bin Wang ◽  
Hong-li Li ◽  
Zhen-ying Cheng ◽  
...  
Keyword(s):  
Measurement Uncertainty ◽  
Conditional Probability ◽  
Probability Model ◽  
Probability Models ◽  
Estimation Formula ◽  
Sampling Inspection ◽  
Measurement Results ◽  
Absolute Probability ◽  
Selection Of

It is important to research into the misjudgment probability of product inspection based on measurement uncertainty, which is of great significance to improve the reliability of inspection results. This paper mainly focused on total inspection and sampling inspection methods and regarded the misjudgment probability as the index to provide quantitative misjudgment risk results for both producer and consumer sides. Through the absolute probability and the conditional probability model, the estimation formula of the total inspection misjudgment rate is deduced, respectively, and the calculation methods of qualification determination and misjudgment rate of the full inspection results are studied. According to the total inspection misjudgment rate, the methods of misjudgment rate of sampling inspection and qualification determination of measurement results are researched. The misjudgment rate of measurement results is calculated based on the exhaustive method and the Monte-Carlo simulation. The estimation results show that the misjudgment probabilities calculated by absolute probability models can be used as the basis for the selection of the measurement plan for product inspection. The misjudgment probability calculated by conditional probability models is more directly to reflect the risks for both producer and consumer sides, and it prompts inspectors to make decisions more carefully.

scholarly journals Mental Experiment in Metrology and Representation of Measurement Uncertainty in a Complex Form

2018 ◽  
pp. 47-49
Author(s):  
V. Chalyy
Keyword(s):  
Measurement Uncertainty ◽  
Thought Experiment ◽  
Complex Form ◽  
Standard Uncertainty ◽  
Measurement Information ◽  
Uncertainty Of Measurement ◽  
Total Uncertainty ◽  
The Real ◽  
Technical Procedure ◽  
Measurement Results

The essence of the thought experiment and its use in metrology for evaluating and presenting measurement results are studied. An imaginary experiment has a hypothetical-deductive structure, carried out on the basis of the developed program, plan-scheme, is based on experience and is based on the real laws of the phenomena under study and does not go beyond the boundaries of empirical preconditions. The term «uncertainty» of measurement is considered in three aspects: quantitative knowledge of objects of the real world, the technical procedure for obtaining pragmatic measurement information, evaluation of the measured information for making informed decisions and risk management. An analyzed of the shortcomings of exis­ting methods to assess the components of measurement uncertainty, based on the specific features of the GUM concept. In this concept, all components of measurement uncertainty are grouped abstractly into two categories - A and B without sufficient justification of the classification criteria. A method for classifying the components of uncertainty based on a real or mental experiment is proposed, and the results obtained are referred to as real (standard) uncertainty «and» imagi­nary (standard) uncertainty». The total uncertainty is considered as a complex value and is calculated on the basis of orthogonal vectors of the results of real and imaginary experiments. The proposed interpretation of the uncertainty of measurement gives a better understan­ding of the nature of uncertainty, simplifies entries and calculations.

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