scholarly journals Ensuring the validity of the results of calibrations and tests by statistical methods

Author(s):  
Alexander Kolbasin

According to the requirements of ISO/IEC 17025:2017, the validity of test and calibration results is ensured, inter alia, by intralaboratory check of the results obtained. In this case, it is preferable to use statistical methods. The ISO 5725 standards define a number of such methods, but the choice of specific methods is left to the laboratory, taking into account the requirements for the adequacy of the effort, resources and time for the purposes of the work performed and the risks of obtaining inappropriate results. In this case, the laboratory itself must in a certain way determine which objects of calibrations (tests) should be predominantly used in checks and what frequency of checks should be foreseen. In connection with the increase in the accuracy and complexity of measuring systems, the need to apply the methods of the theory of random processes becomes more and more obvious. It is shown that the use of the Poincaré plot makes it possible to comprehensively, effectively and visually evaluate changes in the measuring process from the point of view of the dynamics of the obtained measurement results. The results of the check, in particular, the intermediate precision, make it possible to obtain a more realistic evaluation of measurement uncertainty in accordance with ISO 21748. The paper analyses some practical approaches (of varying degrees of complexity) to intralaboratory checks of the validity of calibration (test) results.

2020 ◽  
pp. 43-50
Author(s):  
Yauheniya N. Saukova

It is shown that the issues of metrological traceability for extended self-luminous objects with a wide range of brightness have not yet been resolved, since the rank scales of embedded systems are used for processing digital images. For such scales, there is no “fixed” unit, which does not allow you to get reliable results and ensure the unity of measurements. An experiment is described to evaluate the accuracy of determining the intensity (coordinates) of the color of self-luminous objects. In terms of repeatability and intermediate precision compared to the reference measurement method, the color and chromaticity coordinates of self-luminous objects (reference samples) were determined by their multiple digital registration using technical vision systems. The possibilities of the developed methodology for colorimetric studies in hardware and software environments from the point of view of constructing a multidimensional conditional scale are determined.


1998 ◽  
Vol 14 (04) ◽  
pp. 265-276
Author(s):  
Ivo Senjanovic

This review paper covers extensive investigations which were undertaken in order to verify the idea of launching of ships and other floating structures from a horizontal berth by a set of turning pads. This includes structural dynamics during launching, model tests and strength analysis of the structure and the launching system. The most important results, which were used for the design of the launching system, are presented. The preparation of a barge for side launching is described, and the full-scale measurement results are compared with the test results. The advantages of building ships and offshore structures on a horizontal berth are pointed out in the conclusion.


2018 ◽  
Vol 164 ◽  
pp. 01017 ◽  
Author(s):  
Jalinas ◽  
Wahyu Kusuma Raharja ◽  
Bobby Putra Emas Wijaya

The heart is one of the most important organs in the human body. One way to know heart health is to measure the number of heart beats per minute and body temperature also shows health, many heart rate and body temperature devices but can only be accessed offline. This research aims to design a heart rate detector and human body temperature that the measurement results can be accessed via web pages anywhere and anytime. This device can be used by many users by entering different ID numbers. The design consists of input blocks: pulse sensor, DS18B20 sensor and 3x4 keypad button. Process blocks: Arduino Mega 2560 Microcontroller, Ethernet Shield, router and USB modem. And output block: 16x2 LCD and mobile phone or PC to access web page. Based on the test results, this tool successfully measures the heart rate with an average error percentage of 2.702 % when compared with the oxymeter tool. On the measurement of body temperature get the result of the average error percentage of 2.18 %.


2015 ◽  
Vol 812 ◽  
pp. 375-380 ◽  
Author(s):  
D. Pósalaky ◽  
János Lukács

The magnitude of different aluminium alloys, especially the ones with higher strength, are increasing in the structural engineering, not just the usual applications (like the aerospace industry) but more likely in the automotive industry. There are more assumptions of the effective use of aluminium; we should highlight two important factors, the technological and the applicability criterions. The technological criterion is the joining of structural elements, frequently with welding thus the technological criterion ultimately is the weldability. The assumption of applicability comes from the loading capability of these structures, which is typically cyclic loading so the key issue from the point of view of applicability is the resistance to fatigue. This article represents physical simulation and fatigue test results both on the base material and on the welded joints.


2020 ◽  
Vol 5 (2) ◽  
pp. 138-145
Author(s):  
Ely Kurniati ◽  
Rusnawati

Preeclampsia complicates 4-7% of pregnancies and remains the leading cause of maternal and fetal morbidity and mortality worldwide. Despite improvements in health care over the last decade, preeclampsia remains the second most common cause of maternal mortality in Indonesia. This study aims to determine whether the mean arterial pressure (MAP) is related to the incidence of preeclampsia in pregnant women at the Bontobangun Puskesmas, Bulukumba district for the period 2018 to 2019. This research uses a descriptive-analytic approach with Historical Cohort Studies, namely by looking at the cohort book of the history of blood pressure measurement results for pregnant women at the Bontobangun Public Health Center, Bulukumba Regency for the period 2018 to 2019. Determining the sample using the sampling method taken by purposive sampling. 31 samples of pregnant women who experienced preeclampsia and 31 controls were pregnant women with normal conditions who had certain criteria (matching) with the sample. The results explained that from the paired T-test results, the value of α> 0.037 so that it is said that there is a relationship between mean artery pressure (MAP) and the incidence of preeclampsia in pregnant women at Bontobangun puskesmas for the period 2018-2019.


2009 ◽  
Vol 3 (5-6) ◽  
pp. 101-108
Author(s):  
Éva Bácsné Bába

The role of the time factor in management is increasing. Change directs attention to the time factor from the point of view of the organisation,and management does the same from that of the person. I examined the time management practice of managers of organisations related to agribusiness, and the reaction time characterising the adaption ability of the organisations through a questionnaire survey. I analysed the collected data with scientifically established statistical methods. During studying resources, managing tasks, change, reaction time and effect I explored the features of time as resource, the significance of the time factor, the improvability of time efficiency in the different managing functions, the factors supporting and hindering the quick reaction of organisations, and what rearrangements can be seen in management work nowadays.


2018 ◽  
Vol 1 (1) ◽  
pp. 20
Author(s):  
Indri Nurwahidah

The research was conducted to determine the characteristics and forms of matter; similarly determine the validity, reliability, as well as the students' response to the measurement results HOT reasoning about TIMSS models to measure student HOT developed. The method used is the research development. Products in the form of multiple choice questions as well as the reasons of the students' answers. Student responses obtained from the questionnaire responses the students after using such a matter. Based on the criteria of due diligence in a very good product. Characteristic of reasoning about TIMSS models which contain components reasoning refers to the TIMSS. About the validity of the overall test results show that the question is valid and feasible to use to measure student HOT. Reliability test results indicate that the matter is reliable and can be used well. Student response after use problems in the excellent category, obtained a percentage of 82.66%. HOT measurement results in the category of students is still low, at SMPN 8 Semarang amounted to 51.54%, SMP Kartika III-2 Semarang amounted to 31.16%, and the MTs NU amounted to 47.68% Ungaran. Problem reasoning models that have been developed decent TIMSS used to measure student HOT.


2016 ◽  
Vol 858 ◽  
pp. 91-97
Author(s):  
Jun Hua Xiao ◽  
Wen Qi Zheng

To investigate the macroscopic mechanical properties of undisturbed structural Xiashu loess in the lower reaches of China’s Yangtze River under triaxial compression, and obtain the intrinsic explanations for the macroscopic mechanical properties from the microscopic point of view, in laboratory, triaxial compression tests were carried out, microstructure images of sheared samples were collected by scanning electron microscope (SEM), and quantitative parameters of microstructure (mainly about particle or pore size, distribution, and alignment) were extracted by digital image processing technique. Based on the test results, the deviator stress-strain relationships of both undisturbed and remoulded Xiashu loess, the structural strength, and the microstructural evolution mechanism about the formation of shear failure zone of Xiashu loess under triaxial compression were analyzed.


2021 ◽  
Author(s):  
Dennis Philipp

<p>A height definition in terms of geopotential numbers offers a variety of advantages. Moreover, from the theoretical point of view, such a definition is considered more fundamental. </p><p>We know, however, that relativistic gravity (here General Relativity) requires to reformulate the basic geodetic notions and to develop a consistent theoretical framework, relativistic geodesy, to yield an undoubtedly correct interpretation of measurement results.</p><p>The new framework of chronometric geodesy that builds on the comparison of clocks offers fundamental insight into the spacetime geometry if a solid theoretical formulation of observables is underlying modern high-precision measurements. Here we approach a genuine relativistic definition of the concept of height. Based on the relativistic generalization of geopotential numbers, a definition of chronometric height is suggested, which reduces to the well-known notions in the weak-field limit.</p>


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