Metrological Reliability Research Articles

In-tube extraction dynamic headspace coupled to gas chromatography-mass spectrometry for the sensitive analysis of volatile compounds in aqueous samples

Aim: Volatile organic compounds (VOCs) are often human-made contaminants used and generated in the manufacturing of numerous products, presenting notable environmental and health hazards. Therefore, the development of sensitive and reliable analytical methods is crucial for their detection with accuracy, timeliness, and automation capabilities. The objective of this study is to demonstrate the suitability of the in-tube extraction dynamic headspace (ITEX-DHS) sampling method for the gas chromatographic/mass spectrometric (GC/MS) analysis of BTEX (benzene, toluene, ethylbenzene, and xylenes) compounds in aqueous matrices. It emphasizes the method’s metrological reliability and innovative approach to precisely determining VOCs in aqueous environments providing a tool to prevent contamination of the agrifood sector. Methods: Following the optimization of various experimental parameters, including salt incorporation and adjustments of both dry purging and desorption conditions. The method’s performance was evaluated for repeatability, reproducibility, and robustness. Results: Limit of detection (LOD) and limit of quantification (LOQ) were for all substances determined lower than 50 and 100 ng/L, respectively. Average relative standard deviations below 5% were achieved for all analytes, with recovery rates ranging between 93% and 101%. Subsequently, the method was applied for the determination of BTEX in one hundred groundwater samples. The findings revealed that the BTEX levels were below the LOD in 84.2% of samples. However, in the remaining samples, more than one compound was detected at concentrations higher than the LOQ. Conclusions: The ITEX method emerges as a highly favorable alternative to both solid phase microextraction (SPME) and purge and trap (P & T) methods for determining BTEX in aqueous samples, providing significant advantages. Its strengths lie in its increased robustness, extended trap lifespan, and enhanced sensitivity, underscoring its superior performance in VOC analysis. The total analytical method allows the sensitive and robust determination of VOC.

A novel automated thickness measurement method and device for nuclear fuel plates

The Nuclear and Energy Research Institute (IPEN-CNEN/SP) currently employs manual external u-shape frame micrometers with non-rotating spindles, and chamfered measuring anvils at 21 pre-defined points to control the thickness of its fuel plates. However, it is acknowledged that this method introduces the human element into the measurement process, potentially compromising result accuracy and the integrity of the fuel plates' surfaces. This research introduces a novel thickness measurement method and an accompanying automated device featuring precise movement mechanisms, data capture, transcription, and processing. Our findings emphasize the effectiveness of this new measurement system and the structural integrity of the equipment, highlighting its potential to significantly enhance both the speed and metrological reliability of dimensional control processes for nuclear fuel plates manufactured at IPEN-CNEN/SP.

Automated thickness measurement system for nuclear fuel plates: A metrological study

Thickness measurements of nuclear fuel plates manufactured at the Nuclear Fuel Center of the Nuclear and Energy Research Institute (IPEN-CNEN/SP) are currently performed using manual external U-shaped frame micrometers with non-rotating spindles and beveled measurement anvils. Results are then manually recorded on dedicated forms. To improve the efficiency and the metrological reliability of the process, a novel thickness measurement system for nuclear fuel plates was developed. This work presents a comprehensive metrological study of the newly designed measurement system, achieved through the construction of a new apparatus with automated mechanisms for synchronized movement, data capture, transcription, and processing. The study results demonstrate the metrological adequacy of the developed system and underscore the importance of the design and structural quality of the measurement equipment. Consequently, the metrological reliability of the results in the dimensional control of nuclear fuel plates is confirmed.

Metrological reliability of primary transducers taking into account element stability and accuracy

Metrological reliability of primary transducers taking into account element stability and accuracy

Проблематика оценки глубины асфальтосмолопарафиновых отложений в трубных системах транспортирования нефти

During the operation of oil pipelines, an accumulation of asphalt-resin-paraffin deposits is observed on their inner surface, which significantly reduce the efficiency of their operation. These deposits are a significant obstacle to the activities of oil transportation industries. There are permanently significant funds for the cleaning of oil pipelines of the given negative accumulations. In order to determine the prospects and effective implementation of high-cost treatment measures, there is a need for adequate data on the current thickness of deposits in pipelines. This article compactly presents measuring instruments based on radiation, ultrasonic, dielkometric and thermal measurement methods. At the same time, the main requirement for such measuring instruments is metrological reliability, provided through their intellectualization, in other words, providing them with parameters that make it possible to function under conditions of significant uncertainty, failures and a number of subsystems, which is provided by redundancy. Essential requirements are the safety of operation and ease of operation. The most reliable method of measuring the height of the deposits under study now is an ultrasonic method based on the emission of an ultrasound pulse through the pipeline wall and the registration of signals of their reflection from the opposite wall. The positive side of this approach is the possibility of placing a measuring device on the outer surface of the pipeline without destroying its integrity. The authors concluded that thermal and ultrasonic sensors are maximally suitable for solving these problems, the integration of signals from them makes it possible, in addition to reducing the error when measuring the height of deposits, to increase their reliability, as well as to maintain the survivability of the system in case of a malfunction or disconnection of any of the sensors.

Risk analysis in conformity assessment of positive displacement flowmeter

Volume measurement of manufactured liquids and liquid raw materials carried out by road tankers (RT) is usual and has economic relevance, justifying the need to ensure metrological reliability. It requires some actions, including choosing suitable standards. In this scenario and considering the practice for type evaluation of measuring instruments, the article proposes a case study, analyzing performance data from a positive displacement meter, a measurement principle widely used as a standard in RT verifications. Current criteria of legal metrology were used: for the 0.3 accuracy class, the maximum permissible error (MPE) is 0.2%. The meter was tested with three different fluids (with different viscosities), and measurement errors were contrasted with the MPE specification, being considered compliant in all situations. On the other hand, risk analysis tools for conformity assessment were incorporated (JCGM 106) based on the different consumer risks, the formulated decision rule, and the measurement uncertainty. Even though, when including the risk analysis, the flowmeter was considered non-compliant, showing the need for a better basis decision using measurement uncertainty in legal metrology actions.

Metrological perspective on the use of ultrasound physiotherapy equipment in Brazil

Despite several scientific proofs about the success of using therapeutic ultrasound for different therapies, there are also reports of failures and ineffectiveness in applied treatments. Much of this failure is due to the poor working conditions of the ETUS equipment used, which causes the reduction or absence of therapeutic effects. This survey asked professionals about the methods they use and the methods they know and are available on the market to test their equipment through a questionnaire. This study aimed to discuss, for the metrological perspective, the use of ultrasound physiotherapy equipment in Brazil. A problem for the metrological reliability of ETUS is related to the lack of metrological culture among users, who do not adopt procedures to assess their equipment, often because they are unaware of its importance and need. Periodic checks on equipment would give physiotherapists a resource with greater reliability and possibly more efficient therapies.

THE ROLE OF METROLOGICAL SUPPORT IN INNOVATIVE ACTIVITIES

The transition to new technologies sets a number of new specific tasks determined by the parameters and structure of innovative products to science and technology. Both the technological process of creating innovative products and the measurement of parameters, processing of measurement information, and ensuring the credibility and metrological reliability of measurements need metrological support. The functioning of modern measuring instruments is connected not only with the possibility of a purposeful choice of a rational measurement algorithm in a fixed situation but also with the procedure for making decisions about the nature of further actions. Therefore, fundamental research concerning the design of intelligent measuring instruments is currently being actively conducted in mathematical metrology. The development of an electronic information and analytical system for measuring equipment will ensure the installation of the optimal range of quantitative target indicators and the formation of metrological measures of priority programs and projects. The article considers the possibilities of successfully solving the problems of metrological support for the implementation of innovative technologies. The solution of such problems depends on the completeness, validity, and feasibility of metrological measures. The expediency and necessity of the formation and implementation of metrological measures of innovative technologies are shown. Keywords: Metrology, metrological support, quality, innovative activity, infrastructure, metrological measures, measuring indicators.

On the metrological reliability of subsequent verification of thermal energy meters

Individual metering for heating and cooling has been recognized by EU as an effective tool to improve energy efficiency. Hence, thermal energy meters are widely spreading in district heating networks and in buildings. While type approval and initial verification of thermal energy meters are clearly regulated, no technical standards are available in EU for subsequent verification both in laboratory and in-field. Nevertheless, verification of thermal energy meters is a difficult task, due to the complex measuring chain and to the need to set appropriate verification points combined in flow-rate and temperature difference. In this paper, the authors present the results of an experimental campaign aimed at analysing the metrological issues and compatibility between subsequent verification of a thermal energy meter performed in the laboratory and in-field. The obtained results demonstrate that in-field verification outcomes in some cases are not consistent with the in-laboratory ones.

Comparison of Different Methods to Evaluate Measurement Uncertainty in Bimetallic Thermometers Used in Industrial Equipment

This paper compares different methods (Kragten, Guide to the expression of uncertainty in measurement –GUM– and Relative Uncertainty) to evaluate the measurement uncertainty in bimetallic thermometers. The motivation for the development of the work is based on a need detected in the industry to increase the metrological reliability of thermometers for temperature control in the most diverse measurement processes. The applied methodology is based on the concepts enshrined in the classical literature about the GUM, Kragten and Relative methods. The consolidated results confirmed that, for temperature measurement applications, the GUM method is more appropriate for estimating the measurement uncertainty. The value obtained was equal to 1.22oC throughout the calibration range of the instrument. In conclusion, this work showed that an increase in metrological reliability for the measurement of temperature, fundamental magnitude in industrial processes, can be obtained by evaluating different methods for estimating the measurement uncertainty.

Estimation of Measurement Uncertainty of the Real-Time Location System (RTLS) with Ultra-Wideband (UWB) Technology

The need to control the real-time location of assets is increasingly relevant worldwide. The Ultra-wideband (UWB) technology is an IoT solution for real-time locating systems (RTLS). The location of the asset is obtained by the signal exchange between a wireless tag (asset) and fixed anchors. The tag interacts with the fixed anchors, defining its position through the distances obtained by trilateration. This data is sent to the server through the gateway. It is well-known that this process has several sources of errors. However, the measurement uncertainty assessment of UWB technology is an important topic regarding its scope of use. This paper presents a task-specific measurement uncertainty evaluation for the UWB positioning system, according to the ISO GUM. It aims to propose a method to support decision-making regarding the possible uses of UWB technology. The position provided by the UWB is compared with reference points using Cartesian coordinates that are measured with a total station, providing metrological reliability. Using the information from the estimated uncertainty, one can define the minimum tolerance interval associated with UWB technology for a given use. A case study demonstrates the method.

Application of the method of ordinary least squares in the calibration of temperature, pressure and mass meters

The goal of this paper is applied the Ordinary Least Squares (OLS) method as a strategy in order to reduce the uncertainty measurement associated to the relevant physical quantities. Methodology or method: This work was motivated due to the efforts made in the measurement sciences to investigate alternative methods that allow obtaining greater metrological reliability of the results, that is, reducing the uncertainty associated with the measurement. Thus, the applied methodology consisted of the development of a computational code using the MatLab tool, in which an algorithm was programmed that supports the application of the OLS method. Three of the most used physical magnitudes at an industrial level were evaluated: temperature, pressure and mass. These magnitudes were evaluated from the calibration of three measuring instruments: thermistor, manometer and digital scale. Results: The applied methodology allowed to: (i) obtain the matrix of the coefficients for polynomials of degrees 1, 2, 3 and 4 that adjust the experimental data; (ii) to draw the calibration curves for each of the obtained polynomials and (iii) to estimate the fit uncertainty (i.e.: the mean squared deviation) to specify the polynomial that best models the experimental data for a reliability level of 95.45 % (k = 2). The consolidated results confirmed a reduction in the uncertainty associated with the adjustment polynomial of 99.8% for the temperature measurement, 45.6% for the pressure measurement and 53.9% for the mass measurement. Conclusions: Finally, a discussion of the results is presented, confirming the effectiveness of the ordinary least squares method as a strategy to reduce the uncertainty associated with the calibration of measuring instruments.

Properties and indicators of metrological reliability of measuring items

The issues of metrological reliability of measuring items are investigated. The conceptual terminology of the theory of reliability is analyzed in relation to measuring items. The regulatory and technical requirements for the reliability of measuring items are considered. The classification of failures of measuring items is carried out. A model is constructed in the form of a tree diagram that characterizes the properties and indicators of the reliability of measuring items. The necessity of standardization of regulatory and technical requirements for the metrological reliability of measuring items is substantiated.

CONTROL SYSTEM OF THE TECHNOLOGICAL PROCESS OF FABRICATION SOAP

Today, it is impossible to imagine a complex, modern technological process without the use of an information and measurement system. Without such systems, it is impossible to measure the parameters of the technological process in order to make a timely decision on the need to correct the current values by influencing the technology or the processes taking place during production. Control over changes in technological process parameters is an urgent task of modern measuring equipment. A significant aspect is the maintenance of metrological reliability of such systems. The constant development of element base production technologies makes it possible to develop information and measurement systems not only with high accuracy indicators, but also with high metrological reliability. Also, the systems are becoming cheaper and any enterprise can afford them based on its needs. The primary measuring transducers in such control systems bear the greatest burden on the metrological accuracy of measurement results. This distribution of the contribution to the total measurement error on the part of the sensors imposes special requirements on their technical characteristics. The article presents the control system of the technological process of the manufacture of household soap, which is built using a modern element base, which makes it possible to measure the main parameters of the technological process (object) with high accuracy and act on the object thanks to executive devices. The need for this action is determined by comparing the current value of the monitored parameter with the set point (pre-set critical value). This procedure is performed thanks to the program loaded into the microcontroller. The article provides a structural diagram of the information and measurement system, an elemental base on the example of sensors of monitored parameters, an electrical-principle diagram, as well as an analysis of errors by measurement channels. It has been proven that measurement errors on each of the channels do not exceed the set value of 1,0 %.

DEVELOPMENT OF A SYSTEM FOR MONITORING THE PARAMETERS OF THE ENVIRONMENT DURING SHRIMP BREEDING

Today, information and measurement systems are used in almost all industries where it is necessary not only to measure the parameters of the object of control, but also to absorb the process in the object, in order to respond in a timely manner to changes in controlled parameters. Monitoring changes in the parameters of the object of control is an urgent task of modern measuring technology. When developing an information and measurement system that performs the collection, processing and transmission of information, one of the main tasks is to maintain the metrological reliability of such a system and its economic feasibility. The information and measurement system must be competitive in comparison with existing analogues. One of the promising ways to increase metrological reliability is the use of modern high-precision primary measuring transducers, as it is the analog part of the measuring channel that makes the largest contribution to the total measurement error. The article proposes to develop a system of control of environmental parameters in shrimp breeding on the basis of modern element base, which allows not only to measure with high accuracy the microclimate parameters in the shrimp tank, but also to influence the object of control through actuators. These devices switch on the water heating and aeration system if necessary. Determining the need to influence the environment is determined by the operation "comparison of the current value of the control parameter with the set value". This operation is possible thanks to the software product that is loaded into the microcontroller. The article presents a block diagram of the developed information and measurement system, electrical schematic diagram and analysis of errors in measurement channels. It is noted that the measurement error on each of the channels does not exceed 1.5%.

Development methodology of metrological support of maintenance by the technical state of communication means

Peculiarities of metrological support for technical maintenance based on the condition of large-scale communication devices (tens and hundreds of thousands of elements) consisting of separate subsystems, whose functionality can be checked, maintenance and restoration of functionality can be performed autonomously, are considered. It is suggested to increase the efficiency of technical maintenance according to the condition to take into account the peculiarities of metrological support, to establish a rational sequence of operations, and to reasonably choose measuring equipment depending on the requirements. For this, the methodology uses a complex indicator that combines individual parameters of checks and the probability of their preferred choice. This makes it possible to assess the technical condition of the means of communication in a minimum time with a given probability. In addition, it is possible to quantitatively estimate the time of maintenance, taking into account metrological reliability and the probability of correct assessment of the result of checking parameters by means of measuring equipment. The procedure for using the obtained results is formalized and an example of implementation is given. For the first time, the results of the latest research in the field of technical and metrological support of means of communication during their technical operation are taken into account, namely, the possibility of erroneous assessment of the results of parameter checks, the possibility of failure of measuring equipment, which allows to significantly increase the probability of correct assessment of the technical condition of means of communication during their maintenance according to condition. In addition, taking into account modern achievements in technical diagnostics made it possible to quantitatively estimate the maximum value of the maintenance time based on the state of the means of communication and compare it with the acceptable value specified in the technical documentation. The functional dependencies of the proposed complex coefficient of the feasibility of each inspection, on the metrological reliability of the measuring equipment and the probability of erroneous decisions in the evaluation of the inspection values after measuring the relevant parameters, were obtained and investigated. The area of existence of solutions for calculating the complex coefficient from the quality of metrological support is defined. It is advisable to use the obtained results during the development of the technological process of maintenance of promising and existing means of communication, as well as when planning the activities of specialists during scheduled maintenance work on equipment at field and stationary communication nodes.

Predicting and Determining the Time Between Metrological Failures of Smart Systems for Precision Farming

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.

INSTRUMENTAL ERRORS OF TRANSMISSION LINE PARAMETERS METER

The article is devoted to the construction of the instrumental errors dependences of the transmission line parameters meter on the parameters of the physical or structural hardware components of the meter. For this, when constructing a mathematical model, only the main functional connections between the structural links of the measuring device were selected, neglecting the influence of external factors on the stability of the structural elements parameters. As is know, each measuring instrument must have a certain set of metrological characteristics. According to these characteristics, measuring instruments are selected for use in certain technological processes, and it is they that determine the reliability of the data obtained as a result of measurements. These characteristics include a list of physical quantities that can be measured, the conditions under which the measurement process can be carried out, metrological (informational) reliability, accuracy class or permissible errors of the measuring instrument itself. The conditions under which the measuring instruments can be used depend on the constructive and technological implementation of the device, since the measurement technique and its implementation in the electrical circuit are not accompanied by special requirements for the operation of the device. This means that such a meter can be produced with a focus on laboratory use, for use in a mobile version and in the field, for use in complex electronic systems as an element of built-in control, etc. All this follows from the given measurement technique and analysis of the synthesized meter circuit. The exact characteristics of a measuring instrument include two important components: method errors and instrumental errors. To build such dependencies on the parameters of physical or structural hardware components and the values of the measured quantities, it is necessary to build a mathematical model of the measuring equipment. It is advisable to restrict ourselves to the construction of a mathematical model, which will take into account the dominant factors of the accuracy characteristics that cause first-order errors. Such a model, depending on the needs that arise during the operation of the measuring instrument, can be supplemented by certain sources of influences, certain causal actions that will cause the appearance of errors of the second and even third order. These are errors caused by changes in temperature, humidity, atmospheric pressure, mechanical vibrations, electromagnetic and acoustic fields, etc.

Safety of critical infrastructure objects from the positions of risk effectiveness reduction

In the Ukrainian standards of general risk assessment, according to analogues within ISO, safety aspects are mainly informative. Therefore, both the quality of risk as-sessment and the reduction of its negative consequences (risk effectiveness) depend on the proper use of methods and techniques. that is why in order to prevent unauthorized physical and information access, ie any damage and interference with loss of confiden-tiality, integrity, accessibility, observation, authenticity and reliability of both official information of the organization and the integrity of the production system of the organi-zation with their facilityes of obtaining, processing and storing information, it is neces-sary to make the correct choice of risk assessment method and further ensure the proper implementation of protection in accordance with the reduction of risk effectiveness. The purpose of the work is to substantiate and analyze the proposed structural and linguistic scheme of the methodology of construction of the System of protection and safety of critical infrastructure objects (CIO) from the standpoint of risk effectiveness. From the point of view of reduction of hypothetical negative consequences from risks for regular of CIO the conditions for potential risk criteria are given and the Sys-tem of risk assessment of the security of the set of critical infrastructure objects (SCIO) is considered with access to it, which includes subsystems of: the Ukrainian standards of general risk assessment, declared methods of general risk assessment; assessment of se-curity losses according to confidentiality, integrity, accessibility, observation, authen-ticity, reliability and stability of protection boundaries; filtering of these risks and sup-porting decision-making on access control to SCIO. The advisability of the increased obligations concerning reliability and safety of measuring instruments is proved in order to strict requirements for cybersecurity risk assessment in terms of realization the prin-ciple of uncertainty while ensuring the metrological reliability of measurements.

Analysis of the Metrological Reliability – Study on Simulated and Experimental Data

Analysis of the Metrological Reliability – Study on Simulated and Experimental Data