Вимірювальна техніка та метрологія. – 2015. – Випуск 76
Permanent URI for this collectionhttps://ena.lpnu.ua/handle/ntb/32930
Міжвідомчий науково-технічний збірник.
Вимірювальна техніка та метрологія : міжвідомчий науково-технічний збірник / Міністерство освіти і науки України ; відповідальний редактор Б. І. Стадник. – Львів : Видавництво Львівської політехніки, 2015. – Випуск 76. – 165 с. : іл.
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Item Метрологія, кваліметрія та кваліметричні вимірювання: теорія і практика(Видавництво Львівської політехніки, 2015) Мотало, Василь; Мотало, Андрій; Стадник, БогданРозглянуто й проаналізовані основні проблеми розвитку кваліметрії. Обґрунтовано використання в теорії та практиці кваліметрії концептуального поняття “кваліметричні вимірювання” як одного із видів вимірювань, що дозволяє поєднати методологію кваліметрії та метрології, істотно розширити можливості кваліметрії щодо достовірності й точності отриманих оцінок якості продукції. Розглянуто і проаналізовано основні завдання кваліметрії з оцінювання якості вуглеводневих газів. Рассмотрены и проанализированы основные проблемы развития квалиметрии. Обосновано использование в теории и практике квалиметрии концептуального понятия “квалиметрические измерения” как одного из видов измерений, что позволяет совместить методологию квалиметрии и метрологии и существенно расширить возможности квалиметрии в достоверности иточности полученных оценок качества продукции. Рассмотрены и проанализированы основные задачи квалиметрии в области оценивания качества углеводородных газов. In the article, the main issues of interrelation between qualimetry and metrology reviewed and analyzed. Qualimetry is a branch of science where research subject is product quality quantitative assessment and as an each new science it has some theoretical and methodological problems. Solving these problems, according to the authors, is possible only in a complex combination of quality control methodology and metrology. Metrology, the science of measurement and its application, has the strong scientific, practical and legal tools, which allows research in any field of knowledge. Analysis of the ways of solving these problems is the subject of this study. The authors propose to use the concept of “qualimetrical measurements” as one of the types of measurements in the theory and practice of quality control. That allows combine the methodology of qualimetry and metrology and significantly extend qualimetry opportunities in the reliability and accuracy of the product quality estimates. Qualimetrical measurements, by the authors definition, is indirect measurements of product quality level, the meaning of which can be obtained by the way of measurement results processing of its characteristics according to multidimensional scaling methodology. Product quality level is a relative characteristic of product quality grounding on the comparison of values of products quality assessed indexes and basic values of corresponding indexes. Generally, qualimetrical measurements as any other one consists of two principal stages: • carrying out the measuring experiment during which different characteristics (mechanical, dimensional, electric, magnetic, thermic and chemical composition etc.) of studied products are measured; • measuring experiment results processing during which the studied products quality Q is defined. This is the qualimetrical measurements results. Therefore, the mentioned above approach of qualimetrical measurements essence and purpose enables to treat them as one of the indirect measurements types and to use the main principles of measuring theory for their analysis. The procedure of qualimetrical measurements for measuring of product quality level is developed and its practical implementation described in this article and such tasks of research to achieve the work goal solved: • a synthesis of the product quality measure; • developing of the procedure of qualimetrical measurements; • a synthesis of the one-dimensional qualimetrical scale of product quality level; • a practical implementation of the qualimetrical measurements methodology on the example of the determining the quality level of natural gas as an energy source. The basis of any measurement is the comparison ofmeasured value and measure which reproduce and (or) keeps one ormore known values of a given quantity. Qualimetrical measurements specificity is absence of specific physical (material) quality measures of some products. Product quality virtual measure used formethodological providing of qualimetricalmeasurements procedure realization and their accuracy and quality assessment. Virtualmeasure is the theoretical analog of corresponding physical (material)measure of studied product and it’s the reflection of real physical (material) measure of current product quality is expressed by mathematical and programmeans. In this case, the product quality virtualmeasure is a weighted basic profile of product qualityPK,bz , formed from single relative weighted basic quality indexes Kbz,i , і = 1,2,…,п, where n – number of product quality indexes, equal to the number of properties of the investigated product. To measure the quality level of the investigated product Q, namely for full implementation of qualimetric measurements procedures, it is necessary to compare the weighted estimated profile of product quality PK,oz , formed from single relative weighted estimated quality indexes Koz,i , with weighted basic profile PK ,bz , namely with virtual quality measure. To compare profiles of quality PK,oz and PK,bz is used the methodology ofmultidimensional scaling – one of the sections of mathematical statistics, the subject of research of which is data processing on pairwise similarities, connections and relationship between objects that are analyzed in order to present these objects in the form of points of some multidimensional space. In the case of statistic independent (non-correlated) single relative quality indexes for comparision profiles of quality PK,oz and PK,bz it should be used weighed Euclidean individual differences model. In the case of correlation between the single quality indexes to determine product quality level it should be used three-model multidimensional scalingmodel. In both cases it should be defined the absolute difference or deviation function DП between profiles of quality PK,oz and PK,bz . On the basis of obtained deviations DП the scale of product quality level Q determination can be build, and as result bigger numerical quality Q level value will correspond for higher product quality: Q = 1 –DП or Q = (1 –DП)×100%. Thus, based on the methodology of qualimetrical measurements, developed in the article, the complex evaluation of the Natural Gas quality as an energy source was realized, in which were taking into account a ratio of themost important gas characteristics, such as caloric content, humidity, density, composition, availability and quantity of non-flammable and harmful components.Item Розроблення та аналіз варіантів апаратної реалізації портативних частотних аналізаторів імпедансу(Видавництво Львівської політехніки, 2015) Стадник, Богдан; Хома, Володимир; Хома, ЮрійОписано та проаналізовано три варіанти побудови портативних частотних аналізаторів імпедансу на сучасній елементній базі та розглянуто можливості їх використання в поєднанні із ПК, а саме: на базі спеціалізованих мікросхем AD5933/AD5934, сигнального мікроконтролера STM32F4, програмованої логічної матриці сім’ї Cyclone. Також наведено алгоритми функціонування ЧАІ, з описом процедур калібрування та визначення параметрів АВП, коригування та опрацювання результатів вимірювання. Описаны и проанализированы три варианта построения портативных частотных анализаторов импеданса на современной элементной базе и рассмотрены возможности их использования в сочетании с ПК, а именно: на базе специализированных микросхем AD5933 / AD5934, сигнального микроконтроллера STM32F4, программируемой логической матрицы семейства Cyclone. Также приведены алгоритмы функционирования ЧАИ, включающие описание процедур калибровки и определения параметров АИП, корректировки и обработки результатов измерения. Impedance spectroscopy is widely used to study biological, physical and chemical objects, for example in biomedical measurements, in study of the materials properties, particularly on micro- and nanoscale, for corrosion monitoring and diagnostics, for control of batteries, fuel cells. Often research is carried out on a objects under non-laboratory conditions. A good example of such research is the use of impedance spectroscopy for testing of corrosion-resistant coatings on various steel structures such as bridges, pipelines and other. This leads to the need for cheap, small portable measuring devices – impedance analyzers. A novel concept for design of portable impedance analyzers have been developed in the article. Themain idea is based on minimization of the analog part ofmeasurement channel, aswell as on the replacement of a number of functions to a personal computer. Three variants of design of portable impedance analyzers are described and analyzed in the article. The first option involves the use of single-chip converter AD5933, combined with universal processor Atmega16U2 and external operational amplifier. The hardware implementation is quite simple, but the main disadvantage is limited frequency band (maximum frequency converter AD5933 is 100 kHz). Also this approach has no possibility for tuning and optimization of measuring channel parameters. The second implementation of portable impedance analyzers is based on the STM32F4 digital signal controller with built-in DACs and ADCs, which makes it an extremely attractive in terms of flexibility and simplicity in the design. However, the drawback of this implementation includes limited frequency band (100 kHz). The third option involves the implementation of digital part of the impedance analyzer (CPU, DDS and DSP blocks) on FPGA in combination with external DAC and ADC. This method is the most flexible in terms of configuration, as the digital part enables optimization of measurement channel parameters and DAC and ADC specifications can be chosen according to current application needs. The main disadvantage of this approach is relatively high price and power consumption.