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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Аналіз шкал вимірювань
(Видавництво Львівської політехніки, 2015) Мотало, Василь
Розглянуто й проаналізовані основні питання теорії та принципи систематизації типів шкал вимірювань. Розглянуто види властивостей емпіричних об’єктів та особливості їх прояву і відповідні їм шкали вимірювань. Вибір і використання тієї чи іншої шкали і, відповідно, методики вимірювання залежить від виду вимірюваної величини та способу отримання вимірювальної інформації, тобто способу порівняння розмірів величин. Рассмотрены и проанализированы основные вопросы теории и принципы систематизации типов шкал измерений. Рассмотрены виды свойств эмпирических объектов, особенности их проявления и соответствующие им шкалы измерений. Выбор и использование той или иной шкалы и, соответственно, методики измерения зависят от вида измеряемой величины и от способа получения измерительной информации, т. е. способа сравнения размеров величин. The basic principles of systematization of measurement scales types are describes and analyses in this article. Properties types of the empirical objects and corresponding measurement scales are considered. According to VIM3 (“International vocabulary of metrology: Basic and general concepts and associated terms”), measurement scale (quantity-value scale) is an ordered set of quantity values of quantities of a given kind of quantity used in ranking, according to magnitude, quantities of that kind, for example, Celsius temperature scale, time scale, Rockwell C hardness scale etc. According to the metric determination, depending on the type of the investigated empirical object, in particular, of its properties, and therefore the type of measured value, measurement scales are divided into the following types: nonmetric scales: nominal scales and ordinal scales; metric scales: intervals scales, ratios scales and absolute scales. Metric scales – these are scales, which have the units of measurement (for eg., meter, ampere, m/s). Non-metric scales – these are scales, which do not have units of measurement. According to the form of empirical data obtaining, measurement scales are divided into verbal, numerical and graphic. According to the number of the displayed properties of empirical objects, measurement scales are divided into onedimensional and multidimensional. Nominal scales are formed in the case when a certain property of empirical objects is evident only in respect of equivalence. The main informative parameter of such objects is their quantity (number), which is determined by counting. This feature can be displayed by any number or other mark that does not contain any information about the value size, which is inherent in this property. Nominal scales or scales of names are used in the measurement of objective evidences such as odor, color, blood groups, nationality, marital status, age, gender, work experience, qualifications, telephone numbers, passports, bar codes of products, etc. Ordinal scales are formed in the case when a certain property of empirical objects is shown in relation of equivalence and order (of level). Located according to ascending or descending order, namely, according to the rank, the size of the measured values constitute ordinal scale or rank scale. The ordinal scale or rank scale is expressed in the form of an ordered sequence of points, marked with letters, numbers or symbols that meet certain values size Qі, і=1,2,3,…,п: Q1
Метрологія, кваліметрія та кваліметричні вимірювання: теорія і практика
(Видавництво Львівської політехніки, 2015) Мотало, Василь; Мотало, Андрій; Стадник, Богдан
Розглянуто 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.