scholarly journals Method of kurtosis in estimating the measurement uncertainty during calibration of the electrical resistance measures using a potentiometer

Author(s):  
Igor Zakharov ◽  
Olesia Botsiura ◽  
Valerii Semenikhin

Calibration of electrical resistance measures is considered by the indirect method, which is realized through measuring the voltage drop across the series-connected reference and calibrated resistors. The biases of the estimates of the measurand and the combined standard uncertainty due to the nonlinearity of the measurement model were calculated. The distribution laws of the input quantities in the calculation of the expanded uncertainty were taken into account by the kurtosis method. An example of measurement uncertainty evaluating during calibration of single-size electrical resistance measure R331 with a nominal resistance of 1000 Ω by comparing its value using a potentiometer R345 with the value of the calibrated reference standard is considered. Estimates of the measurand and its standard and expanded uncertainties obtained using the proposed method showed good agreement with the estimates obtained using the Monte Carlo method.

2009 ◽  
Vol 59 (7) ◽  
pp. 1409-1413 ◽  
Author(s):  
T. Higuchi

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.


2020 ◽  
Vol 12 (8) ◽  
pp. 1050-1053
Author(s):  
Jasveer Singh ◽  
L. A. Kumaraswamidhas ◽  
Neha Bura ◽  
Kapil Kaushik ◽  
Nita Dilawar Sharma

The current paper discusses about the application of Monte Carlo method for the evaluation of measurement uncertainty using in-house developed program on C++ platform. The Monte Carlo method can be carried out by fixed trials as well as adaptive trials using this program. The program provides the four parameters viz. estimate of measurand, standard uncertainty in the form of standard deviation and end points of coverage interval as an output.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Adriaan M. H. van der Veen ◽  
Juris Meija ◽  
Antonio Possolo ◽  
David Brynn Hibbert

Abstract Many calculations for science or trade require the evaluation and propagation of measurement uncertainty. Although relative atomic masses (standard atomic weights) of elements in normal terrestrial materials and chemicals are widely used in science, the uncertainties associated with these values are not well understood. In this technical report, guidelines for the use of standard atomic weights are given. This use involves the derivation of a value and a standard uncertainty from a standard atomic weight, which is explained in accordance with the requirements of the Guide to the Expression of Uncertainty in Measurement. Both the use of standard atomic weights with the law of propagation of uncertainty and the Monte Carlo method are described. Furthermore, methods are provided for calculating uncertainties of relative molecular masses of substances and their mixtures. Methods are also outlined to compute material-specific atomic weights whose associated uncertainty may be smaller than the uncertainty associated with the standard atomic weights.


2020 ◽  
Vol 26 (3) ◽  
pp. 469-483
Author(s):  
Nicholas W. M. Ritchie

AbstractThis is the first in a series of articles which present a new framework for computing the standard uncertainty in electron excited X-ray microanalysis measurements. This article will discuss the framework and apply it to a handful of simple, but useful, subcomponents of the larger problem. Subsequent articles will handle more complex aspects of the measurement model. The result will be a framework in which sophisticated and practical models of the uncertainty for real-world measurements. It will include many long overlooked contributions like surface roughness and coating thickness. The result provides more than just error bars for our measurements. It also provides a framework for measurement optimization and, ultimately, the development of an expert system to guide both the novice and expert to design more effective measurement protocols.


Author(s):  
S. G. Khan ◽  
◽  
L. K. Ibrayeva ◽  
N. V. Syabina ◽  
Z. M. Yuldashev ◽  
...  

To create conditions for the recognition of Kazakhstani certificates of conformity and the results of product tests, an assessment of measurement uncertainty is required. In this regard, there has been an increase in the practical application in Kazakhstan of the concept of measurement uncertainty. The authors developed a physical stand for a mobile complex designed to verify electromagnetic flowmeters at the place of operation. To obtain verification results, programs were developed to calculate the uncertainty of an electromagnetic flowmeters using the NI LabView software. In addition, a model for estimating the uncertainty of the relative error of flowmeters was proposed, and the measurement uncertainty was estimated using three methods: standard, Monte Carlo and Kragten. Finally, a comparative analysis was conducted on the results of the estimation of the uncertainty of the relative error of the industrial electromagnetic flowmeter. All methods give standard uncertainty values that do not exceed the acceptable range of relative error (± 1%). However, Monte Carlo method gives better results for sufficiently large number of simulations. No significant differences between the results obtained using standard and Kragten methods were discovered. The Kragten method is preferable in the absence of the need to calculate the sensitivity coefficients when calculating the total standard uncertainty, which is important for complex measurement equations.


1973 ◽  
Vol 52 ◽  
pp. 187-189
Author(s):  
P. Cugnon

This paper is devoted to a comparison between results obtained by Purcell and Spitzer (1971) using a Monte-Carlo method and by the author (1971) using a Fokker-Planck equation. It is shown that there is a good agreement between the results within the dispersion expected from the Monte-Carlo method.


2020 ◽  
Vol 26 (3) ◽  
pp. 484-496
Author(s):  
Yu Yuan ◽  
Hendrix Demers ◽  
Xianglong Wang ◽  
Raynald Gauvin

AbstractIn electron probe microanalysis or scanning electron microscopy, the Monte Carlo method is widely used for modeling electron transport within specimens and calculating X-ray spectra. For an accurate simulation, the calculation of secondary fluorescence (SF) is necessary, especially for samples with complex geometries. In this study, we developed a program, using a hybrid model that combines the Monte Carlo simulation with an analytical model, to perform SF correction for three-dimensional (3D) heterogeneous materials. The Monte Carlo simulation is performed using MC X-ray, a Monte Carlo program, to obtain the 3D primary X-ray distribution, which becomes the input of the analytical model. The voxel-based calculation of MC X-ray enables the model to be applicable to arbitrary samples. We demonstrate the derivation of the analytical model in detail and present the 3D X-ray distributions for both primary and secondary fluorescence to illustrate the capability of our program. Examples for non-diffusion couples and spherical inclusions inside matrices are shown. The results of our program are compared with experimental data from references and with results from other Monte Carlo codes. They are found to be in good agreement.


Author(s):  
Kerim Tuna Ikikardaslar ◽  
Mahmoud K. Ardebili ◽  
Feridun Delale

Glass fabric epoxy resin based composite panels enhanced with carbon nanotubes were subjected to damage while changes in electrical resistance were obtained via embedded electrodes. The purpose of the study was to develop an alternative method to Electrical Impedance Tomography (EIT), which generates conductivity field, hence, indicating presence of various damages. The current method provides damage field by taking meticulous measurements of electrical resistance of panel. The method does not monitor conductivity as in the EIT but utilizes electrical resistance changes to detect damage. In the current form, it employs a network of 64 (8 × 8 grid) electrodes distributed evenly in a typical panel instead of the boundary electrodes used in EIT. Even though 64 electrodes were employed, fewer electrodes were sufficient to produce accurate indication of damage location and its size. In previous studies percolation threshold for carbon nanotube-epoxy mixture was determined, which enabled selection of optimal CNT concentration used in manufacturing of glass fiber reinforced panels. The glass fiber reinforced panels were manufactured by vacuum infusion method. The typical panel consisted of 10 glass fabric (S-2) plies. Copper electrodes were embedded beneath the top layer fabric ply. Electrical resistances measurements were obtained using four-probe technique. In the four-probe method, two outer electrodes are used to source a known current through the panel, while the two inner electrodes provide voltage drop needed to compute resistance. The technique minimizes contact resistance between electrodes and the composite, which could be order of magnitude larger than the material resistance being measured. Electrical resistance of cured glass fiber reinforced CNT-epoxy panels was first measured without any damage. Afterwards, damages in form of circular hole were inflicted to the panel starting with 1/8” diameter and enlarging it to 1/2” in steps of 1/8”. After the largest hole, 0.04” (∼1 mm) width cracks emanating from the hole were inflicted. During all measurements, electrical current passing through the source and sink electrodes was kept constant and changes in voltage from the inner probes were recorded. The thrust of the method is to incorporate a curve fit for quantifying the changes in resistance. The method can be applied to damage quantification in panels. The smaller spaced electrode distribution was more sensitive to smaller damages as expected, but the larger spaced electrodes network was sufficiently responsive to smallest damage. Experimental results were fairly good at predicting the damage and its magnitude. Results also indicated a very good agreement with the finite element simulations of the panels. Application of this technique can be a powerful tool for real time structural health monitoring of manufactured composites.


2018 ◽  
Vol 199 ◽  
pp. 11016
Author(s):  
Keiyu Kawaai ◽  
Isao Ujike

Electrical resistance tomography (ERT) has been studied for visualizing variations of conductivity in concrete specimens. In recent years, unsaturated water flow through pores formed in concrete has been intensively examined though ERT systems to visualize the permeation front that gradually changes with elapsed time. This study examines water movement through internal cracks which are typically not observed on the surface of mortar or concrete specimens via ERT systems. The results indicate the gradual increase of saturated region owing to the ingress of water through cracked surface up to 120 hours. And, the region with higher conductivity estimated in uncracked parts is evidently in good agreement with higher moisture content measured by moisture meter on the split surface. In addition, the presence of crack in concrete specimen subjected to water ingress is clearly visualized via ERT images owing to rapid water movement in cracked zones. This study has provided the important insight that the ingress and the movement of water through pores and cracks formed in cementitious mixtures could be assessed via electrical measurements.


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