Metrological Problems Research Articles

In order to reduce the number of erroneous water management decisions, it is necessary to have sufficiently strict metrological support for studies of the composition and properties of natural waters. The use of standard methods requires expanding the scope of hydromonitoring and increasing the accuracy of the data obtained in order to ensure their representativeness, including the ability to refl ect general trends and transfer the results of the study to a wider range of objects. As a possible alternative to standard methods, it is proposed to analyze the accumulated measurement information using fuzzy logic. A methodology for applying the methods and mathematical apparatus of fuzzy (multi-valued) logic to solve metrological water-ecological problems has been developed and tested using the example of water quality assessment. Using fuzzy logic methods, the infl uence of four cause factors “Leaching”, “Weathering and sedimentation”, “Anthropogenic discharges”, “Self-purification” on the effect factor “Decrease in water quality against background” in the fi ve-level Harrington scale adopted in expert statistical assessment was studied. Using the software package of fuzzy logic MatLab Fuzzy Logic, forecasts of changes in water quality depending on four factors were obtained. The method of assessing the quality of natural water was tested on a specific example of setting up a fuzzy system for assessing water quality.It was found that the risks of errors still exist, but they were significantly reduced by taking into account poorly formalized linguistic information from expert hydrologists. The possibility of using the method for an a priori assessment of the probable consequences of changes in factors infl uencing the decline in water quality and taking preventive measures to optimize the operation of the water use system was shown.

Quantum sensors offer control flexibility during estimation by allowing manipulation by the experimenter across various parameters. For each sensing platform, pinpointing the optimal controls to enhance the sensor's precision remains a challenging task. While an analytical solution might be out of reach, machine learning offers a promising avenue for many systems of interest, especially given the capabilities of contemporary hardware. We have introduced a versatile procedure capable of optimizing a wide range of problems in quantum metrology, estimation, and hypothesis testing by combining model-aware reinforcement learning (RL) with Bayesian estimation based on particle filtering. To achieve this, we had to address the challenge of incorporating the many non-differentiable steps of the estimation in the training process, such as measurements and the resampling of the particle filter. Model-aware RL is a gradient-based method, where the derivatives of the sensor's precision are obtained through automatic differentiation (AD) in the simulation of the experiment. Our approach is suitable for optimizing both non-adaptive and adaptive strategies, using neural networks or other agents. We provide an implementation of this technique in the form of a Python library called qsensoropt, alongside several pre-made applications for relevant physical platforms, namely NV centers, photonic circuits, and optical cavities. This library will be released soon on PyPI. Leveraging our method, we've achieved results for many examples that surpass the current state-of-the-art in experimental design. In addition to Bayesian estimation, leveraging model-aware RL, it is also possible to find optimal controls for the minimization of the Cramér-Rao bound, based on Fisher information.

Quality control of quantitative diffusion-weighted magnetic resonance imaging: metrological problems

In contrast to traditional X‐ray photoelectron spectroscopy (XPS), hard X‐ray photoelectron spectroscopy (HAXPES) can provide information from deeper within a sample while maintaining chemical resolution. However, working with higher energy X‐rays introduces a series of new or different issues ranging from energy calibration to factors associated with quantitative analysis. As part of the efforts to identify and increase community awareness about these issues, a workshop was held to review HAXPES metrology challenges with the perspective of converting it into a quantitative technique. A summary is hereby given of this workshop, which was entitled “What New Challenges Come with the Capabilities of HAXPES?” It was held in Portland, OR, USA, on November 7, 2023, and was primarily sponsored by the ASTM E42 Committee and the Applied Surface Science Division of the American Vacuum Society. This report contains summaries of the presentations and discussions at this workshop regarding the current open problems in HAXPES metrology. There were 20 participants at the workshop.

Quantitative magnetic resonance imaging is a modern method for detecting pathological changes in the patient’s tissues. However, images with quantitative characteristics are not widely used due to the limitation of the accuracy and reproducibility of the measured values. The purpose of this work is to formulate the metrological problem of quantitative magnetic resonance imaging and to ensure the reliability of research based on the analysis of practical approaches to quality control of diffusion-weighted magnetic resonance imaging. As part of the work performed, an analysis was carried out of the use of phantoms as means to ensure quality control of certain parameters of quantitative magnetic resonance imaging. The importance of validation was noted, the metrics used to control the quality of quantitative magnetic resonance imaging were highlighted, an overview of examples of clinical studies using diffusion-weighted magnetic resonance imaging was presented. It was found that accurate calibration and testing of magnetic resonance imaging scanners, as well as verification of image analysis tools, are necessary for the use of quantitative magnetic resonance imaging data in clinical practice.

The article presents a summary of knowledge on the research and metrological problems related to the assessment of features and parameters of weapon systems. The basic metrological problem of research laboratories evaluating weapon systems is related to the constant search for new solutions, building unique test stands and seeking metrological equipment with higher accuracy classes than the equipment of military weapon systems which is subject to assessment. This is very difficult for the military technology to perform, even impossible in many cases. Significant research problems raised in the article also concern the study of descriptive and functional features which are not addressed by metrology. The article is an introduction to the commencement of works on the extension of metrology related to measurements and evaluation of the results obtained in research laboratories during the implementation of procedures related to the testing of descriptive and functional indicators. The information included in the article may be a source of knowledge for both the personnel of military laboratories and the personnel of civilian laboratories.

Objectives. Quality control of instruments for measuring bactericidal irradiance of ultraviolet (UV) radiation is based on studying the main metrological characteristics. These characteristics include: angular and spectral sensitivity; linearity range; and absolute calibration in irradiance units. Deviations of the angular sensitivity of measuring instruments from the ideal cosine characteristic can significantly impact error estimation. They can also lead to the distortion of measurement results and a significant difference in instrument readings. The aim of this work is to enhance accuracy in resolving metrological problems of determining irradiance of bactericidal radiation.Methods. An effective method of resolving this problem is to introduce correction coefficients for the angular sensitivity of radiometers, spectroradiometers and dosimeters. The values are calculated based on the results of measurements on the goniometer when testing measuring instruments. An important role is played by computer models and digital twins of measuring instruments based on the results of studies of the metrological characteristics of radiometers by means of software. This includes modeling the measuring task.Results. The study of angular dependence of bactericidal UV radiometer sensitivity complemented by an analysis of measurement results obtained by other authors allows determining the value of the angular sensitivity correction coefficients by the deviation of the angular sensitivity of the irradiance measuring instruments of bactericidal radiation from the standard cosine dependence.Conclusions. Deviations of the angular dependence of bactericidal radiation UV radiometer sensitivity from the cosine characteristic lead to a significant underestimation of the irradiance measurements results from extended emitters. An effective solution is the use of digital angular sensitivity correction coefficients to measure the irradiance of bactericidal radiation determined during tests. When assessing the quality of radiometers, spectroradiometers and dosimeters for bactericidal radiation, incomplete control of the main metrological characteristics of the measuring instruments creates risks of serious errors in the measurement results of bactericidal irradiance.

An overview of the legal framework of metrology at the international level, in particular, the activities of the intergovernmental International Organization of Legal Metrology, is given. The establishment of the International Organization of Legal Metrology has had an impact on the consolidation of the regulatory framework for metrology at the regional level, especially in the European Union. The reliability, comparability and traceability of measurement results are ensured by international regulatory documents developed by countries in the field of activity of seven international organizations. For international recognition of measurement and test results of any country. There is a need for a system of normative instruments that ensure international law. Strategically, it is necessary to create a legal framework so that it is possible to move from regional politics to global politics. The role of legal metrology at the regional level and the formation of the legislative framework of fundamental metrology in the world are described. The article presents a database of basic documents for solving scientific problems of ensuring the uniformity of measurements at the international level and the main milestones in the history of the formation of the legal framework of the measurement system in Russia for two centuries. The creation of the metrological service of the USSR, and then the state system for ensuring the uniformity of measurements determined new approaches to improving legislation in the field of metrology. Harmonization of the language of measurements and approaches to solving the problems of metrology will ensure the uniformity of measurements not only in individual countries and regions, but also on a global scale.

The European Metrology Network MATHMET is a network in which a large number of European national metrology institutes combine their forces in the area of mathematics and statistics applied to metrological problems. One underlying principle of such a cooperation is to have a common understanding of the ‘quality’ of software, data and guidelines. To this purpose a flexible, lightweight Quality Management System (QMS), also referred to as Quality Assessment Tools (QAT), is under development by the EMN. In this contribution the application of the QMS to several use cases of different nature by VSL is presented. The benefits and usefulness of the current version of the QMS are discussed from the particular viewpoint of a particular employee of VSL, and an outlook for possible future extensions and usage of the QMS is given.

ABSTRACT Intercultural sensitivity is the affective dimension of intercultural competence. Recently, the Intercultural Sensitivity Scale (ISS) was validated for Korean samples, which raised conceptual, translational, and metrological problems. This study improved on the previous ISS Korean version, developed the Respect for Diversity Scale (RDS), and reanalysed the results according to gender and school level. The sample comprised 542 native Korean-speaking high school and college students. Both scales confirmed the validity of 12 items across four dimensions. Notably, the mean ISS scores exceeded those of the RDS across most factors. Gender differences exhibited significance in the scores of both scales, while school-level differences did not prove significant. This study contributes to the literature that has adapted and validated the ISS with participants from non-English-speaking cultures. Additionally, it sheds light on the relationship between the ISS and measures of general diversity appreciation, highlighting variations based on participants’ background characteristics.

In this article, the data on metrological supply issues of electric energy and production enterprises and laboratories in modern economic conditions are analyzed. Methods of choosing a measuring instrument and reducing errors are analyzed and recommendations are given.

Relevant metrological problems of monitoring radiation in water, as well as other types of radiation measurements, are mainly related to insufficient status of measures of specific activity (standard solutions of radionuclides) and limited calibration capabilities in laboratories and standardization organizations in different regions of Russia. If there are no certified reference materials and measurement standards adequate for a measurement task, then metrological traceability of measurements can be carried out according to calibration procedures regulated by measuring methods using calibration standards prepared as certified mixtures from calibrated solutions of radionuclides, as well as pure uranium and potassium compounds. Regular interlaboratory comparisons with control samples having reference quantity values of the measured parameters allow laboratories to confirm their technical competence and the metrological traceability of measurement results.

Introduction. Solving the problem of forecasting and determining the operating time for metrological failure and conducting the first calibration of smart systems of precision land use is possible by solving the problem of self-calibration of smart sensors that are part of these smart systems (SS). This problem is solved and described in [1]. The purpose of the paper is the methodology for dynamic prediction and determination of the time between metrological failures (MF) and the first verification of SS designed for precision farming. Results. The article describes a method patented in Ukraine for measuring the SS operating time for a MF (dynamic prediction method) based on a synthesized probabilistic-physical model (PP-model) of SS MF described by a multi-parameter Kondratov – Weibull distribution function (DF) with controlled (flexible) parameters. The proposed model describes the relationship between the normalized error and the parameters of the metrological reliability (MR) of the SS. It is shown that the dynamic regression PP-models of MF are a combination of the capabilities of regression models using flexible multi-parameter DF, with the possibility of using dynamic (spatio-temporal) processes covering different trends in the change in the values of normalized errors and their uncertainty bands, confidence level, time frame, acceptable boundary conditions, etc. Dynamic regression models of MF SS make it possible to understand the relationship between DF variables and allow the possibility of studying metrological problems (“scenarios”) of the “what if …” type. The dynamic regression method is a set of techniques for reciprocating approximation of the values of the shift parameter of the dynamic PP-model of MF to the predicted value of the shift parameter of the static PP-model of MF SS, as well as methods for assessing the reliability and accuracy of forecasting and determination. The article describes the essence of a new method for determining the operating time of the SS in the MF using the PP-model of the MF based on the Kondratov – Weibull DF. For the first time, a graphical portrait of the PP-model of SS metrological failures in the combined system of scales (coordinates) has been developed and presented - with the scales "probability of metrological failure Pξ" and "normalized error ξx" and separate or combined scales of "interval time scale tx " and "calendar time scale". The procedure for determining the time of the first verification is described, the advantage of non-periodic verifications is noted in order to save costs for their implementation. The possibility of occurrence of "conditional misses" in determining the error and time of operation on the MF during one or another verification is shown. Their existence is established only after the subsequent verification, analysis of the obtained data, and drawing the curve of the DF on a graphical portrait. It is recommended to choose the time between verifications as a multiple of one year, and to carry out verifications on the same day and month of the year. Conclusions. The dynamic regression method is an effective and versatile method due to the high accuracy of forecasting and determining the operating time in the MF. It can also be implemented using MF PP- models based on the DF of Kondratov - Cauchy, Kondratov - Laplace and others. Keywords: smart sensor, self-calibration, wireless sensor systems, methods of redundant measurements, problems of metrological support.

Objectives. In order to solve fundamental metrological problems concerning the reproduction and transmission of spectral radiometry units, as well as developing methods and tools for metrological support of modern technologies such as nanophotolithography in the electronics industry, synchrotron radiation can be used. When developing solid-state sources and receivers of radiation, new topical problems arise in connection with the metrological characteristics of light-emitting diodes (LEDs), multi-element array receivers, charge-coupled device (CCD) cameras and telescopes, whose successful solution depends on the properties of a reference source of synchrotron radiation. Therefore, the purpose of the present work is to develop spectral radiometry methods for obtaining metrological channels using an electron storage ring in order to control the characteristics of electronics components, as well as for studying and calibrating radiometers, photometers, and emitters operating in the visible, ultraviolet and infrared regions of the electromagnetic spectrum.Methods. Methods for transmitting spectroradiometric units on an electron storage ring are based on the classical theory of Julian Schwinger, which describes the electromagnetic radiation of a relativistic electron to calculate the spectral and energetic synchrotron radiation characteristics taking polarization components into account.Results. The possibility of developing methods for transmitting spectral radiometric units using synchrotron radiation was evaluated by means of a test setup, which included a monochromator-based comparator, a telescope with a CCD array, a spectroradiometer, a radiometer, a photometer, a goniometer, and an integrating sphere. This allowed the full set of spectroradiometric and photometric characteristics of radiation sources and receivers to be measured: from the most differential distribution of the spectral radiance density of the emitting region to the integral radiation flux. The results were compared with the reference synchrotron radiation source.Conclusions. Among possible approaches for determining the metrological characteristics of LED emitters, multielement array receivers, CCD cameras, and telescopes, synchrotron radiation seems to be the most promising. This approach allows the small size of the emitting region of synchrotron radiation, the Gaussian distribution of radiance over the emitting region of the synchrotron electron bunch, as well as the wide dynamic range of spectrum tuning due to changes in the energy and number of accelerated electrons, to be taken into account.

General Problems of Metrology and Measurement Technique Metrological Aspects of Harmonic Self-Organization

In this paper, we discuss the prospects for the use of statistical analysis methods in the study of correlations and statistical memory effects in the experimental data of physical experiments. Developed methods under consideration: Memory Functions Formalism and Flicker-Noise Spectroscopy allow obtaining a large set of quantitative parameters and qualitative characteristics directly from temporal signals generated by complex physical systems. Additionally, for the study of collective phenomena and effects, one- and two-parameter cross-correlation functions are proposed, which allow studying cross-correlations between simultaneously recorded signals in spatially separated areas of the object under study. The introduced analytical relations and numerical algorithms can be applied to solve the problems of metrology of surface structures at the nano- and microlevels, to study collective phenomena in the plasma of astrophysical objects, the structure of molecules, and their complexes.

This article deals with methods for measuring the characteristics of ionizing radiation in solving problems of radiation monitoring of the environment, industrial premises, sanitary protection zones, human pollution control using measurement techniques certified in the prescribed manner. The types of measuring instruments involved in the measurement of various quantities are listed. The main objects of measurements used in radiation monitoring of the environment, control of surface contamination and human contamination are named. The metrological characteristics (measured quantities) of measuring instruments are compared with the metrological characteristics of real measurement objects. A number of necessary established metrological characteristics for radiometric and spectrometric measuring instruments for the successful use of a measuring instrument in solving one or another problem of radiation measurements is indicated. An example from a real work is considered, in which the method of mathematical modeling when calculating additional metrological characteristics showed a significant discrepancy with the real data obtained during the experiment.

General Problems of Metrology and Measurement Technique Static Component of Temperature Error in the Strain-Gauge Balance: Determination of the Temperature Sensitivity Coefficient

Metrological support of photon radiation fields of low-intensity and near-background levels (0.04–100 μSv/h (μGy/h)) by ambient equivalent dose rate or kerma rate in air using scintillation detectors with NaI(Tl) crystals looks promising and in demand in dosimetry, but nontrivial due to the complex dependence of efficiency registration of gamma quanta from energy. The solution of such problems with the use of these detectors can be based on the use of the radiation response functions, which are functionals of the energy distribution of the radiation field fluence.
 The paper proposes a method for calculating the radiation response function adapted for solving metrological support problems for creating high-precision dosimetric measuring instruments based on scintillation detection units with NaI(Tl) crystals.

Nowadays, constructing effective statistical estimates with a limited amount of statistical information constitutes a significant practical problem. The article is devoted to applying the Bayesian scientific approach to the construction of statistical estimates of the parameters of the laws of distribution of random variables. Five distribution laws are considered: The Poisson law, the exponential law, the uniform law, the Pareto law, and the ordinary law. The concept of distribution laws that conjugate with the observed population was introduced and used. It is shown that for considered distribution laws, the parameters of the laws themselves are random variables and obey the typical law, gamma law, gamma - normal law, and Pareto law. Recalculation formulas are obtained to refine the parameters of these laws, taking into account posterior information. If we apply the recalculation formulas several times in a row, we will get some convergent process. Based on a converging process, it is possible to design a process for self-learning a system or self-tuning a system. The developed scientific approach was applied to solve the measuring problems for the testing measuring devices and technical systems. The results of constructing point estimates and constructing interval estimates for these laws' parameters are given. The results of comparison with the corresponding statistical estimates constructed by the classical maximum likelihood method are presented.