UNCERTAINTY OF THE MEASUREMENTS RESULTS OF THE CHEMICAL COMPOSITION AND ITS METHODS ASSESSMENT

2021 ◽  
pp. 84-91
Author(s):  
F.N. Karachevtsev ◽  
◽  
A.F. Letov ◽  
A.V. Slavin ◽  
◽  
...  

An explanation of the difference between the uncertainty and the error of the measurement results, which is in the approach to their assessment, is given. The standard and expanded uncertainty are estimated taking into account the uncertainty at each operation to transfer the size of a physical quantity from a standard (standard sample) to a measuring instrument and during measurements. The error is estimated based on the variance of the final measurement. Methods for evaluating the uncertainty of measurement results are given depending on regulatory documents, metrological characteristics, measurement methods, such as indicators and limits of repeatability and reproducibility.

2021 ◽  
Vol 21 (5) ◽  
pp. 136-141
Author(s):  
Przemysław Otomański ◽  
Eligiusz Pawłowski ◽  
Anna Szlachta

Abstract The paper presents a possible application of integrated LabVIEW environment to the final evaluation of measurement results in direct measurement. The possibilities of presenting and visualizing the uncertainty of measurement results in a convenient and user-friendly form are also discussed. The topics discussed in the paper were presented using a developed application in LabVIEW. The paper discusses the topic of measurement of direct voltages in the presence of strong electromagnetic interferences. These problems are frequently omitted or hardly emphasized. It presents a suitable measuring system, a virtual measuring instrument created in the LabVIEW environment, and the results of tests carried out for an example NI PCI-6221 data acquisition board. The described approach can be applied also in other measurement situations.


ACTA IMEKO ◽  
2016 ◽  
Vol 5 (4) ◽  
pp. 88
Author(s):  
Petri Juhani Österberg ◽  
Martti Heinonen ◽  
Maija Johanna Ojanen-Saloranta ◽  
Anssi Jaakko Mäkynen

This article compares the performance of an NMR-based and a microwave based moisture measurement instruments designed for biomaterials. The conventional moisture measurement method, Loss-on-Drying (LoD) serves as a reference measurement for both instruments. Six different biomaterials at three moisture content levels were measured with the microwave instrument and five biomaterials with the NMR instrument. After instrument calibrations, the difference and variation of the measurement results for parallel samples and the repeatability of the NMR and microwave instruments were estimated. Reasonable agreement between the measurement methods was achieved.


2013 ◽  
Vol 718-720 ◽  
pp. 984-988
Author(s):  
Zhi Qing Gao ◽  
Nai Qi Shen ◽  
Xu Li ◽  
Zong Yun Shu

Measurement uncertainty in the water content test for soil samples is an index for evaluating the reliability of the experiment. It affects the accuracy of some parameters such as porosity and saturation, which are derived from water content. According to the requirements of the standard JJF 1059-1999 Uncertainty Evaluation and Denotation of the Measurement Results, the uncertainty for the measurement results of the water content in soil samples was evaluated. Concerning the characteristics of the water content determination in soil samples, a pail of soil sample was taken as specimen due to its relative homogeneity. The factors affecting the measurement accuracy were discussed. The result shows that the expanded uncertainty of measurement results of the water content in soil samples was 1.6% under the proposed testing conditions.


2021 ◽  
Vol 26 (1) ◽  
pp. 67-77
Author(s):  
Seif M. Osman ◽  
Gouda M. Mahmoud ◽  
Abdulelah A. Binown ◽  
Hamad Alghamdi

This is an experimental work on seventy load cells which aims to highlight the difference between results out of force, proving instruments calibration according to ISO 376:2011 and its practical use. It spots on the difference between the relative error of repeatability and reproducibility and their contributions on load cells classifications, uncertainty estimation and calibration time. Results show that there is no significant effect for relative error of repeatability on load cell classification, ignoring the relative repeatability error in estimating the relative expanded uncertainty lead to decrease with values between 1 ppm and 270 ppm in the range from 20 % to 50 % of load cell capacity and by values between 1 ppm and 183 ppm in the range from 50 % to 100 % of the load cell capacity. It is concluded that performing measurements to calculate the relative error of repeatability is not effective in the normal calibration process for the examined seventy load cells, further measurements over subsequent years are recommended to ensure results reproducibility aiming to generalize the conclusion and recommend measurements for the relative repeatability error for load cell conformity assessment after manufacturing.


2021 ◽  
Vol 906 (1) ◽  
pp. 012027
Author(s):  
Erik Sombathy ◽  
Estevao Mendes ◽  
Qianrui Huang

Abstract The main goal of this article is to analyze the possibility of using precise inclinometry for landslides. Inclinometric measurements are widely used to monitor landslides, retaining walls, piles and in places where it is necessary to measure deep ground deformations. The value of deep-seated ground deformations is calculated indirectly by using the difference of the inclination of an inclinometer casing installed on a borehole. Inclinometers are used to measure horizontal movements at various levels, usually within earth fills. Inclinometers are used to monitor slopes, indicating movement on a slope before it is visible on the surface of the slope. Inclinometers have often proved very successful in recognizing movement zones and the size, speed and direction of movement not only on slopes, but also on embankments, etc. There are a number of different types of inclinometers, and within each type there are variations produced by different manufacturers. However, the basic principle of precise inclinometry is the same. A guide tube is installed in the borehole and the inclination of the guide tube from the vertical is measured at predetermined intervals. It is measured using a pendulum which is enclosed in a watertight probe. The probe is lowered through the tube. The inclination of the pendulum is measured using electronic devices that are very accurate. The measurement results are determined by pulling out the measuring instrument (inclinometric probe). After assessing the measured values, the course of the profile is determined, if we compare the profiles from different measurements, we can evaluate the direction and size of the shift for the monitored period.


2015 ◽  
Vol 39 (2) ◽  
pp. 199-202
Author(s):  
Wojciech Batko ◽  
Renata Bal

Abstract The assessment of the uncertainty of measurement results, an essential problem in environmental acoustic investigations, is undertaken in the paper. An attention is drawn to the - usually omitted - problem of the verification of assumptions related to using the classic methods of the confidence intervals estimation, for the controlled measuring quantity. Especially the paper directs attention to the need of the verification of the assumption of the normal distribution of the measuring quantity set, being the base for the existing and binding procedures of the acoustic measurements assessment uncertainty. The essence of the undertaken problem concerns the binding legal and standard acts related to acoustic measurements and recommended in: 'Guide to the expression of uncertainty in measurement' (GUM) (OIML 1993), developed under the aegis of the International Bureau of Measures (BIPM). The model legitimacy of the hypothesis of the normal distribution of the measuring quantity set in acoustic measurements is discussed and supplemented by testing its likelihood on the environment acoustic results. The Jarque-Bery test based on skewness and flattening (curtosis) distribution measures was used for the analysis of results verifying the assumption. This test allows for the simultaneous analysis of the deviation from the normal distribution caused both by its skewness and flattening. The performed experiments concerned analyses of the distribution of sound levels: LD, LE, LN, LDWN, being the basic noise indicators in assessments of the environment acoustic hazards.


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Xiaowei Wang ◽  
Feng Liang ◽  
Degang Zhao ◽  
Zongshun Liu ◽  
Jianjun Zhu ◽  
...  

Abstract Three InGaN/GaN MQWs samples with varying GaN cap layer thickness were grown by metalorganic chemical vapor deposition (MOCVD) to investigate the optical properties. We found that a thicker cap layer is more effective in preventing the evaporation of the In composition in the InGaN quantum well layer. Furthermore, the quantum-confined Stark effect (QCSE) is enhanced with increasing the thickness of GaN cap layer. In addition, compared with the electroluminescence measurement results, we focus on the difference of localization states and defects in three samples induced by various cap thickness to explain the anomalies in room temperature photoluminescence measurements. We found that too thin GaN cap layer will exacerbates the inhomogeneity of localization states in InGaN QW layer, and too thick GaN cap layer will generate more defects in GaN cap layer.


Author(s):  
Leonas Paulauskas ◽  
Robertas Klimas

Rapidly growing urbanization causes the increase of noise level of various sources, that have a negative impact upon people's health. The contribution of noise caused by motor transport in city environment composes up to 80% of general impact of all the sources. The article presents the results of modeling of the spread of motor transport noise of Šiauliai city, maps of motor transport noise, recommendations for management of environment noise. MapNoise programme module, adapted to work in the ArcGIS Desktop 9.1 environment, was used for modeling motor transport noise. Noise measurement researches have been carried out using digital noise isolator Nor121, completed with digital level detector. NorXfar software was used to send the data to personal computer. Having evaluated the validity of modeling results it has been determined that the difference between the night noise modeling and measurement results does not exceed 2.2%, and varies from 0.5dB(A) to 1.1 dB(A). The obtained results indicate that 7.2% of the apartments of all city residents are influenced by the LDEN noise that exceeds the permitted noise level (LDEN >65 dB(A)) and 31.2% of the apartments of the residents are influenced by night noise that exceeds the permitted noise level (LN > 55 dB(A)). Santrauka Sparčiai vykstant urbanizacijos procesui, kinta įvairių šaltinių keliamo triukšmo lygis, didėja neigiama įtaka žmonių sveikatai. Miestų aplinkoje iki 80 % visuminio visų triukšmo šaltinių poveikio tenka autotransporto keliamam triukšmui.Straipsnyje pateikta autotransporto triukšmo sklaidos Šiauliuose modeliavimo rezultatai, autotransporto triukšmo žemėlapiai, aplinkos triukšmo valdymo rekomendacijos. Autotransporto triukšmui modeliuoti naudotas MapNoise programinismodulis, pritaikytas darbui ArcGIS Desktop 9.1 aplinkoje. Iš rezultatų matyti, kad 7,2% visų miesto gyventojų būstų yra veikiami paros triukšmo, viršijančio leidžiamąjį triukšmo lygį (LDVN > 65 dB(A)), ir 31,2% gyventojų būstų veikiami nakties triukšmo, viršijančio leidžiamąjį triukšmo lygį (LN > 55 dB(A)). Įvertinus modeliavimo rezultatų patikimumą nustatyta, kad paros ir nakties triukšmo modeliavimo ir matavimo rezultatų neatitiktis neviršija 2,2 % ir svyruoja nuo 0,5dB(A) iki 1,1dB(A). Резюме При быстром росте урбанизации увеличивается уровень шума, создаваемого разными источниками и отрицательно влияющего на здоровье населения. Шум от автотранспорта в городах составляет около 80% от всех источников шума. В статье представлены результаты моделирования рассеяния шума от автотранспорта в городеШяуляй, карты автотранспортного шума, рекомендации по управлению шумом в окружающей среде. Приизмерении шума был использован числовой анализатор шума № 121, укомплектованный с числовым детекторомуровня RMS. Для передачи данных в персональный компьютер использована программа NorXfer. Для моделирования автотранспортного шума использован программный модуль MapNoise, приспособленный дляработы в среде ArcGIS desktop 9.1. При анализе достоверности результатов моделирования было установлено, чтоих отличие от результатов измерения шума в течение суток и ночное время не превышает 2,2% и колеблется от0,5дБ(A) до 1,1дБ(A). Результаты исследования свидетельствуют о том, что 7,2% жилых помещений городаподвергаются суточному шуму, уровень которого превышает допустимый (LDVN > 65 дБ(A)) и 31,2% жилыхпомещенийгородаподвергаютсяшумувночноевремя,уровень которогопревышаетдопустимый (LN > 55дБ(A)).


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.


Sign in / Sign up

Export Citation Format

Share Document