Microsoft Word - Article 7 - 193-1072-1-PB.docx ACTA IMEKO May 2014, Volume 3, Number 1, 23 – 31 www.imeko.org ACTA IMEKO | www.imeko.org May 2014 | Volume 3 | Number 1 | 23 Theoretical, physical and metrological problems of further development of measurement techniques and instrumentation in science and technology D. Hofmann, Y.V. Tarbeyev Friedrich -Schiller- University, 32 Ernst-Thälmannring, 69 Jena, GDR Section: RESEARCH PAPER Keywords: metrology, measurement technology, measurement theory, standards, fundamental physical constants, uniformity of measurements Citation: D. Hofmann, Y.V. Tarbeyev, Theoretical, physical and metrological problems of further development of measurement techniques and instrumentation in science and technology, Acta IMEKO, vol. 3, no. 1, article 7, May 2014, identifier: IMEKO-ACTA-03 (2014)-01-07 Editor: Luca Mari, Università Carlo Cattaneo Received May 1st, 2014; In final form May 1st, 2014; Published May 2014 Copyright: © 2014 IMEKO. This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited 1. INTRODUCTION The conversion of science into a major productive force is inevitably accompanied with growing interest in increasing measurement accuracy. Many objective studies of reality are reduced to measurements. At the same time the results of scientific research serve as a basis for the further development of this reality. Experimenters in science and practical engineers are interested in higher measurement accuracy, in technical improvement of measuring instrumentation and in higher reliability of measurements. These aspects make up the object of metrology. The task of meeting the urgent requirements of science and technology is the motive force for the progress of metrology and improvement of systems of units and standards which in the long run should provide for an optimum metrological assurance. This capacious concept includes not only the establishment of standards per se but also the development of most efficient methods of dissemination of the values of units and metrological supervision of the correctness of measurements as well as the development of up-to-date measuring transducers, fast automatic measuring systems that require minimum metrological supervision [1]. Metrology is a science, whose scope of knowledge is extremely polytechnical. It should embrace a wide range of electromagnetic, optical, mechanical, physical and chemical, nuclear and many other phenomena and incorporate an immense number of measuring problems that cover measurement transformations, estimation of measurement results and uncertainties, realization of the units of physical quantities and their dissemination. Therefore, it is not difficult to foresee that the task of establishing metrology as an independent science enjoying full rights and having its own large domain of specially arranged knowledge, theorems, methods of investigation, is complicated. The practical requirements and continuous growth of the role of measurements urgently demand that the progress of metrology must be accelerated. The aim of the present paper is to show the directions and ways of the further development of metrology. As examples you will become acquainted with some actual problems of modern metrology and measurement theory. 2. COMMON TRENDS IN THE DEVELOPMENT OF RESEARCH AND APPLICATION IN THE FIELD OF METROLOGY AND MEASUREMENT TECHNOLOGY In the 20th century natural, technical and social sciences have become a decisive productive force. As a result of such This is a reissue of a paper which appeared in ACTA IMEKO 1979, Proceedings of the 8th IMEKO Congress of the International Measurement Confederation, “Measurement for progress in science and technology”, 21-27.5.1979, Moskow, vol. 3, pp. 607–626. Common interest of both metrologists and representatives of science and technology in constant improvement of measurements as well as general trends in the development of research in the field of metrology, measurement technology and instrumentation at the present-day stage are shown. Problems of general metrology, of improving systems of units and standards (“natural” standards in particular) are considered in detail. ACTA IMEKO | www.imeko.org May 2014 | Volume 3 | Number 1 | 24 sharp increase in the practical role of sciences, more and more technical subjects go over from empirically descriptive representation of the observed facts to generalizing theoretical considerations and concepts. In doing so, the peculiar features of the modern progress in scientific research are: – a sharp increase in the use of systems approach to all problems – an increase in the scope and intensity of fundamental research in the total volume of research work. The above-mentioned statements are not only valid for metrology, but are also especially characteristic of the present stage in its development. It is determined by substantial qualitative and quantitative changes. The most prominent quantitative changes are: 1. An increase in the number of measurements and in the number of fields in which measurements are employed. Practically, there are no technical fields where measurements are not made; the measurement expenses reach 50 to 60% of the total production expenses in the most advanced industries (Figure 1) [2]. 2. Measurements provide indispensable technical key information for evaluating and controlling specialized cooperative production. They are carried out on a large scale and provide the decision criteria for acceptance or refusal of labor having been realized in masses. 3. Natural, technical and social sciences operate an instrument technique possessing industrial dimensions and demanding universal knowledge as well as a concerning behaviour of the scientists (in the fields of nucleonics, microelectronics, space research, radiology, electron-scan microscopy, psychological behavior research). Planned experiments are intended to prove the correctness of theoretical considerations. 4. Measurements have two main functions:  an increased observability of preferred technical-physical- chemical states or procedures, widely exceeding the natural limit being set to the sensing organs of the measuring persons.  the objectivation of observations made by measuring persons. It is achieved by comparing measured quantities with known and settled standards. Qualitatively new requirements concerning measurement theory are additionally caused by the following facts: 5. The accuracy of measurements required both in scientific experiments and in industry is more and more approaching the level of standard measurements. 6. Due to the high sensitivity of measuring instruments the environmental conditions and external influencing factors are producing ever-increasing effects on the measurement results. 7. Sophisticated measuring systems whose calibration by traditional methods presents big problems are becoming widespread. 8. Greater sophistication of measuring instrumentation in respect of both the operating principle and the design features makes still higher demands of its operators. Thus, today in measurements, measurement technology and instrumentation take place those qualitative and quantitative changes which not only require the proper investigation of individual metrological problems but also inevitably result in an urgent need for the development of a general theory of metrology and, first of all, a general (unified) theory of measurements. The development of a general measurement theory is complicated by the following state of affairs: 1. Measurement science has a long history and therefore a mighty tradition. In our days this tradition is still aimed at a further differentiation. 2. Measuring has two different definitions:  measuring in a narrow sense, that is experimental comparing of a measured quantity to a known comparison quantity of the same kind (quality) which had been determined to be the unit of measurement. The measurement of physical quantities and the use of ratio scales are typical procedures. (Figure 2) [3]. Figure 1. Acquisition of measurement information in production. ACTA IMEKO | www.imeko.org May 2014 | Volume 3 | Number 1 | 25  measuring in a wide sense is the coordination of numbers with states or procedures, following some rule. Scaling technical and no technical matters without special knowledge and using low value scales are typical procedures (Figure 2) [3]. At measuring in a narrow sense the subjective influence of the measuring person can little by little be diminished. This does not apply to measuring in a wide sense. At measuring you will observe disadvantages and inaccuracies if it is not considered  that each quantity is always a quantity of a certain quality  that the coordination of numbers with objects is also possible without knowing their quality  that formal operating with numbers for any data you like (measured values or non—measured values) is possible and  that mathematical models cannot express themselves if they represent correct facts or arbitrary phenomena [3, p. 37]. 3. Historically we are just beginning to provide generalized knowledge in the fields of measurement engineering and measurement theory. The example of mass measurement is to prove that. Already 2500 B.C. the equal-armed balance had been graphically represented in a pyramid in Gizeh in ancient Egypt. About 300 B.C. Aristotle, Euclid and Archimedes provided the theory for this balance. Electromechanical balances, with strain gages and radiometric balances are developments of the 20th century [4, 5]. 4. The special language of measurement engineering comprises a great number of terms. Numerous terms have not yet been well defined. Synonyms and polysems are frequently used [5]. Classifications and teaching conceptions in measurement engineering have the following points of view:  measured quantities (length, force, temperature measurement engineering)  measuring devices (strain-gage, oscillograph and digital measurement engineering)  measurement principles (isotope, ultrasonic, infrared measurement engineering)  field of measurement (production, process, laboratory measurement engineering). 3. PROBLEMS OF THE GENERALIZED MEASUREMENT THEORY Topical tasks of measurement theory are 1. To increase the uniformity of measurements 2. To assure correct measurements 3. To get valid models of measurements and its aims. Working with models has methodical advantages. In contrast to the originals (measured signals, measuring systems and measurement processes) models are simpler, cheaper, more easily described, can be transformed in time and space, varied, limited and optimized. As a rule, modelling is associated with a certain simplification of the original. For example, a certain body is characterized by the following properties: length, surface roughness, volume, mass, density, temperature, colour, etc. Usually, only selected parameters of the object are considered exactly. Physical (homolog) models transform the scale of the original only or just simplify the original; the measured quantities of the original and model coincide. Mathematical (analog) models describe similar (analog) processes in different fields of knowledge; the measured quantities of the original and model do not coincide. Models consist of a certain number of elements and relations (links) between them. A great advantage is that in gaining knowledge and building up a theory the originals of different nature can produce similar images that allow a uniform treatment and interpretation. In any case the knowledge that was gained using a model in the image field should be confirmed in practice for the actual object. Otherwise the value of this knowledge is subject to argument. The measurement theory deals mainly with well-defined or poorly-defined models of behaviour [6] expressed as algorithms. These models describe:  measured signals and measuring systems in terms of mathematical algorithms,  measurement processes in terms of heuristic algorithms. Figure 2. Classification of scales and their properties after [3]. ACTA IMEKO | www.imeko.org May 2014 | Volume 3 | Number 1 | 26 Specific features of mathematical algorithms are determinism, finiteness, universality and guarantee of solution [7]. Heuristic algorithms are not associated with such strict requirements and still they guarantee only a solution probability 0