Application of systems thinking to the establishment of metrological traceability chains

International agreements in the field of metrology and accreditation of calibration laboratories are the basis for establishing global metrological traceability. Important elements of metrological traceability are calibration of measurement standards and measuring instruments, assessment of measurement uncertainty. The International Laboratory Accreditation Cooperation has a specific policy regarding on traceability of measurement results and estimation of measurement uncertainty in calibration. The partial concept diagram around metrological traceability in accordance with the International Vocabulary of Metrology is proposed. This diagram contains a total of nine metrological concepts, which have most of the associative relations. There are associative relations between the concept of metrological traceability chain and concepts of metrological traceability, measurement standard, calibration and calibration hierarchy, and through the concept of measurement standard with the concept of measurement uncertainty. Systems thinking to the analysis of state of proposed terminological system around metrological traceability was applied. For construction of generalized metrological traceability chain, all the established properties of the system elements around the terminology system of metrological traceability were taken into account. Generalized metrological traceability chain for different levels of the calibration hierarchy was proposed. The proposed chain can be used to develop appropriate chains for specific areas of measurement. To achieve this, it is necessary to determine the specific measured value, the required measurement uncertainty for different levels of the calibration hierarchy and select the necessary measurement standards. Such schemes should be used in national metrology institutes and calibration laboratories.

ANALYSIS OF THE ERROR COMPONENTS OF LEVER TYPE FORCE-GENERATING MACHINES

The national standards are the basis of the technical base of the state metrological system. The developing of a na-tional primary standard of force unit solves such tasks as ensuring the uniformity of force measurements, transmitting the size of a unit of force with the required accuracy, metrological support of a large fleet of working standards and measuring instruments used in Ukraine. One of the main stages in the creation of the national standard is the development of a mathematical model of the process of reproducing the unit size of a physical quantity, namely N - Newton. The purpose of this study is to analyze the components of the error of force-generating installations of the multi-lever type, which are part of the national standard. Force generating installations used by calibration laboratories are usually traced to national standards through verification using precision force transducers. Calibration of force measuring instruments will typically be performed on these installations according to a documented procedure, such as ISO 376, and the components of error and uncertainty of calibration results will depend on the calibration and measurement capabilities of the unit size reproduction. Similarly, the uncertainty of the calibration of industrial force measuring in-struments will depend in part on the uncertainty contributing by the force measuring instrument, and the uncertainty of any subsequent force measurement will depend in part on the uncertainty associated with the reproduction of a unit of force, including national standard. It can be seen that the uncertainty of the final strength measurement depends on all previous stages of the measurement, and this work aims to make recommendations on how these contributions can be estimated. The purpose of this study is to analyze the components of the error of power plants of the multi-lever type, which are part of the state standard. The paper analyzes the method of reproduction, storage and transmission of the unit size, lever reinforcement installations, which can be used as reference metrological institutes and calibration laboratories. The basic principles of operation of the above reference installations are considered and the mathematical model of reproduction of the size of unit of force is created.

Организация системы менеджмента качества лабораторий с учетом требований ГОСТ ISO/IEC 17025-2019 с применением ЛИМС

The updated version of the ISO/IEC 17025 standard has introduced substantial changes to the structure, terminology, requirements to resources, processes, and quality management system of testing and calibration laboratories. New requirements were established for organization of laboratory activities – the process based approach and risk-targeted thinking, which provides for the cutting of some part of the prescriptive requirements and introduction of requirements based upon analysis of actions performed. In accordance with GOST ISO/IEC 17025-2019, the laboratory is required to provide risk identification and assessment processes, develop risk control measures and expand opportunities to achieve the established purposes and objectives. The standard requires the laboratory to plan and perform actions to manage risks and opportunities associated with laboratory activities. This article deals with organization of the quality management system of Transneft system organizations’ laboratories in the aspects of risk management, management of opportunities, corrective actions with the use of laboratory information management system (LIMS). The model of the process implementation is described, subject to requirements of GOST ISO/IEC 17025-2019. Обновленная редакция стандарта ISO/IEC 17025 внесла существенные изменения в структуру, терминологию, требования к ресурсам, процессам, системе менеджмента качества испытательных и калибровочных лабораторий. Были установлены новые требования к организации деятельности лабораторий – процессный подход и риск-ориентированное мышление, что предусматривает сокращение части предписывающих требований и введение требований, основанных на анализе выполнения действий. В соответствии с ГОСТ ISO/IEC 17025-2019 от лаборатории требуется обеспечить процессы идентификации и оценки рисков, разработку мер по контролю рисков и расширению возможностей для достижения поставленных целей и задач. Стандарт требует от лаборатории планирования и реализации действий по управлению рисками и возможностями, связанными с лабораторной деятельностью. В настоящей статье рассматривается организация системы менеджмента качества лабораторий организаций системы «Транснефть» в части управления рисками, возможностями, корректирующими действиями с применением лабораторной информационной менеджмент-системы (ЛИМС). Описана модель реализации процесса с учетом соблюдения требований ГОСТ ISO/IEC 17025-2019.

The New Dimension to Resolution: Can it be resolved?

In the metrology community, there is an ongoing debate over which contributors to the Unit Under Test (UUT) belong in the expanded uncertainty calculation of the measurement process used for calibration. This is also known as Calibration Process Uncertainty (CPU); CPU is the denominator when calculating a Test Uncertainty Ratio (TUR). This paper presents examples that illustrate why the best practices outlined in documents such as ILAC-P14:09/2020 and the ANSI/NCSLI Z540.3 Handbook should be followed regarding the contributors for the CPU. Instead of drafting their own test protocols and standards, calibration laboratories and manufacturers are advised to correctly calculate both uncertainty and risk. Performing these calculations is part of an ethical approach to calibration that avoids shifting more risk to the Industry and ultimately mitigates global consumer's risk. Furthermore, outdated approaches to calculations, such as Test Accuracy Ratio (TAR), must be discontinued, and efforts to change the agreed-upon definition of Test Uncertainty Ratio (TUR) should cease since modern computing can provide measurements that are more accurate and reliable.

Design, Construction and Validation of a High-Performance OATS

The state of the art on the open-area test site (OATS) has been introduced. Key technologies on the design and validation of a high-performance OATS have been provided. Some famous OATS in the world regarding their structure, the dimensions of the ground plane (GP), the location of the control room, and performance are listed in a table. A case study is provided on NIM’s high-performance OATS. Many details are open for the first time, which show the fine design. A measurement uncertainty example has been provided in measuring the free-space antenna factor of biconical antennas. These results are based on the author’s many years of experience, with lots of valuable data and photos. It is intended for calibration laboratories, for EMC antenna users, for writing EMC standards, as well as for the assessors in EMC.

The Data Evaluation of Interlaboratory Comparisons for Calibration Laboratories

National accreditation agencies in different countries have set quite strict requirements for accreditation of testing and calibration laboratories. Interlaboratory comparisons (ILCs) are a form of experimental verification of laboratory activities to determine technical competence in a particular activity. Successful results of conducting ILCs for the laboratory are a confirmation of competence in carrying out certain types of measurements by a specific specialist on specific equipment. To obtain reliable results of ILC accredited laboratories, it is necessary to improve the methods of processing these results. These methods are based on various data processing algorithms. Therefore, it is necessary to choose the most optimal method of processing the obtained data, which would allow to obtain reliable results. In addition, it is necessary to take into account the peculiarities of the calibration laboratories (CLs) when evaluating the results of ILС. Such features are related to the need to provide calibration of measuring instruments for testing laboratories. The evaluation results for ILCs for CLs are presented. The results for all participants of ILCs were evaluated using the En and z indexes. The obtained results showed that for the such ILCs it is also necessary to evaluate the data using the z index also.

Sub-theory of Standardization of Forensic Activity in the General Theory of Forensic Science

The article presents the main provisions of the sub-theory of standardization in the forensic expert activity, its place in the theoretical foundations of forensic expertology, and its relationship with other sub-theories of this science.The author defines the concepts of the subject, the object of the standardization sub-theory in forensic activity, highlights its specifics. The article emphasizes the favorable impact on the development of domestic standardization in forensic activities of foreign experience in the implementation of theoretical developments on standardization, including the formation of a hierarchy of its standards. It is shown that for the development of the sub-theory of standardization in forensic science, it is advisable to use the results of the introduction of standardization mechanisms in the practice of accredited forensic laboratories under the international standard GOST ISO/IEC 17025-2019 “General requirements for the competence of testing and calibration laboratories”, taking into account the theoretical foundations of forensic science.

THE SCOPE OF ACCREDITATION OF THE FORENSIC LABORATORY: THE CONCEPT AND PATTERNS OF CHANGE

The purpose of the research work is to analyze the advantages and disadvantages of the «flexible» field of accreditation of forensic laboratories and the field of accreditation that has a rigid range. The development of standardization in forensic science, including the expansion of the number of forensic laboratories that build their activities in accordance with the requirements of the international standard GOST ISO/IEC 17025-2019 «General requirements for the competence of testing and calibration laboratories», encourages us to pay attention to this issue again. In the course of the study, the following conclusions were formulated. Insufficient clarity in defining the «flexible» scope of accreditation and differences in the understanding of its boundaries by the accreditation body, the forensic laboratory and the customer can lead to abuse by individual laboratories and the development of unfair competition. This argument in favor of abandoning the «flexible» field of accreditation for forensic laboratories seems to be much more weighty than the listed advantages of its practical application.

Evaluation of Shock Tube Retrofitted with Fast-Opening Valve for Dynamic Pressure Calibration

Accurate dynamic pressure measurements are increasingly important. While traceability is lacking, several National Metrology Institutes (NMIs) and calibration laboratories are currently establishing calibration capacities. Shock tubes generating pressure steps with rise times below 1 µs are highly suitable as standards for dynamic pressures in gas. In this work, we present the results from applying a fast-opening valve (FOV) to a shock tube designed for dynamic pressure measurements. We compare the performance of the shock tube when operated with conventional single and double diaphragms and when operated using an FOV. Different aspects are addressed: shock-wave formation, repeatability in amplitude of the realized pressure steps, the assessment of the required driver pressure for realizing nominal pressure steps, and economy. The results show that using the FOV has many advantages compared to the diaphragm: better repeatability, eight times faster to operate, and enables automation of the test sequences.