The Basics of metrological support. Scientific bases of metrological support. Organizational basis of metrological support.

Lecture 2

Objectives of metrological support. The main tasks of metrological support. Tasks of metrological provision Solved experts on the lifecycle of products. Metrological provision of pre-production.

Metrological providing— establishment and application of the scientific and organizational bases, technical means, rules and norms necessary for achievement of unity and the demanded accuracy of measurements.

Main objectives of metrological providing are:

improvement of quality of production, effective management of production and level of automation of productions;

ensuring interchangeability of details, knots and units, creation of necessary conditions for cooperation of production and development of specialization;

increase of efficiency of research and developmental works, experiments and tests;

ensuring reliability of the account and increase of efficiency of use of material values and energy resources;

increase of efficiency of actions for prevention, rationing and control of working conditions and life of people, to environmental protection, assessment and rational use of natural resources;

increase of level of automation of management of transport and safety of its movement;

quality providing and reliability of communication.

The state committee in the field of standardization, metrology and quality of production, carries out the solution of the following main objectives of metrological providing:

definition of the main directions of development of metrological providing and ways of the most effective use of scientific and technical achievements in this area;

development of scientific and methodical, technical and economic, legal and organizational bases of metrological providing at all levels of management of a national economy;

the organization and carrying out basic scientific researches for research and use of new physical effects for the purpose of creation and improvement of methods and measuring instruments of the highest accuracy and determination of values of physical constants;

ensuring unity of measurements in the country, standardization of basic provisions, rules, requirements and norms of metrological providing, development and improvement of GSI;

establishment of units of physical quantities allowed to application;

establishment of system of the state standards of units physical, sizes, their creation, statement, improvement and storage;

establishment of a uniform order of transfer of the sizes of units of physical quantities from the state standards to all measuring instruments;

development of interindustry programs of metrological providing and organization of works on their implementation;

scientific and methodical management of development of comprehensive programs of metrological providing branches of a national economy;

creation and improvement of working standards and model measuring instruments of the highest accuracy, planning and coordination of development of complex testing installations and laboratories;

establishment of uniform requirements to metrological characteristics
measuring instruments; ,

establishment of an order, planning and carrying out the state tests of the measuring instruments intended for mass or mass production and their input from abroad by parties, the statement of types of the measuring instruments allowed to application in the USSR;

state checking of measuring instruments;

establishment of the general requirements to standard samples of structure and properties of substances and materials;

implementation of the management of public service of standard help data, public service of standard examples of substances and materials, public service of time and frequency and ensuring their development;

state supervision of production, state, application and repair of measuring instruments, and observance of metrological rules, requirements and norms, and also of activity of departmental metrological services;

organization and performance of especially exact measurements;

the organization and implementation of preparation and professional development of shots in the field of metrology;

the organization of works on the international cooperation in metrology, ensuring unity and the demanded accuracy of the measurements necessary for international trade, scientific and technical and economic cooperation;

coordination of works on metrological providing with needs of defense of the country;

the organization and implementation of scientific and technical information in the field of metrological providing and exhibiting at a constant exhibition of the measuring instruments intended for mass or mass production and import from abroad by parties.

The solution of the main objectives in the field of metrological providing at the branch level carries out the ministry (department).

It is possible to distinguish two groups from these tasks: problems of ensuring unity of measurements and additional, specific to activities for metrological providing a task which treat:

choice of the nomenclature of parameters of meterial, products, the processes which are subject to an assessment at measurements, tests and control;

choice of the nomenclature and numerical values of indicators of the accuracy (reliability) of results of measurements, tests and control, the forms of their representation providing the optimum solution of tasks for which these results are intended;

metrological examination of project, design and technological documentation for the purpose of control of correctness of results of the solution of two previous tasks;

planning of processes of measurements, tests and control, development of measurement techniques, tests and control;

ensuring processes of measurements, tests and control by the appropriate technical means (measuring instruments, test equipment, control devices);

maintenance of technical means in metrological working order;

performance of processes of measurements, tests and control, processing of results of measurements, tests and control (when it is required).

Unlike tasks of ensuring unity of measurements which decision is assigned to bodies of metrological service, various professional categories, production divisions and collectives have to solve additional group of problems of metrological providing:

choice of the rational nomenclature of the measured (controlled) sizes, parameters - designers, developers of new materials, products or processes on the basis of studying and their modeling (materials, products or processes) of properties;

choice of norms of accuracy - "consumers" of measuring information, i.e. for whom are intended and who will make, exchange (at trade) or to use new substances, products or processes;

metrological examination - professionally prepared Troupes of experts including designers, technologists and specialists of departmental metrological services;

shinirovaniye and carrying out measurements, tests and control - the scientific and technical personnel which is developing and carrying out technological processes of production of materials and products;

ensuring processes of measurements, tests and control with technical means - in the centralized order of the ministry (department), being developers of measuring instruments, tests and control; in decentralized (for example, non-standard measuring instruments and control, the test equipment) — the enterprises and the organizations which are carrying out operations of measurements, tests and control;

maintenance of technical means in good repair — the organizations and the enterprises which are carrying out repair of measuring instruments, tests and control.

Thus, all departmental bodies and technical services connected with "production and consumption" measuring information with standard and instrument ensuring processes of its receiving have to participate in the decision of this group of problems of metrological providing.

We will stop on a choice of the nomenclature and numerical values of indicators of the accuracy (reliability) of results of measurements, tests and control of the forms of their representation providing the optimum solution of tasks for which these results are intended in more detail. In this connection we will consider concept about the optimum accuracy of measurements chosen for a concrete class of measuring tasks according to certain technical and economic reasons.

For example, the choice of norms of accuracy of measurements which results are used at quality control of production, is dictated by the allowed values of probabilities of marriage of control (probabilities to reject suitable and to pass an unusable product). The accuracy of izmeryoyiya is higher, the probability of marriage of control and the less economic losses connected with repeated (unproductive) control suitable and operation of defective products is less. However increase of accuracy of measurements demands material inputs. Therefore, in this case such accuracy of measurements with which the sum of costs of ensuring control (with an optimum accuracy) and economic losses from possible marriage of control will be minimum will be optimum.

Thus, activities for metrological providing any scientific, technical and social tasks have to be based on the basis of the certain technical and economic indicators characterizing its level, efficiency and influence on the general criteria of quality of the solution of these tasks (the full system of such indicators is not developed now yet and it is the major problem on a joint of metrology, economy and the organization of production).

The ultimate goal of metrological providing, as appears from stated above, - to reduce possibility of adoption of wrong decisions on results of measurements, tests and control of raw materials, materials, products and processes to a rational minimum.

Achievement of this purpose requires the complex solution of all problems of metrological providing.

Lecture 3

The Basics of metrological support. Scientific bases of metrological support. Organizational basis of metrological support.

Concepts of unity and accuracy of measurements" are defining for theoretical metrology and metrological practice. Distinction and at the same time interrelation, interconditionality of these concepts define character, the contents, an orientation and forms of the organization of metrological providing any and production problems.

Possibility of application of results of measurements for the correct and effective solution of any measuring task is defined by the following three conditions:

1) results of measurements are expressed in the established units and (or) forms;

2) values of indicators of accuracy of these results are known (with the necessary set reliability);

3) values of indicators of accuracy provide optimum (according to the chosen criteria of an optimality) the solution of a task for which these results are intended.

If results of measurements meet the first two conditions, everything is known of them that it is necessary to know for adoption of the reasonable decision on possibility of their use. Such results can be compared. They can be used in various combinations, various people and the organizations. In this case it is possible to tell that the unity of measurements, i.e. such condition of measurements at which their results are expressed in the established units and (or) forms and an error of measurements is provided are known with the set probability.

If results of measurements do not possess any of these properties i.e. their accuracy is unknown or incorrectly determined, results of measurements, actually unsuitable for the solution of these or those measuring tasks, can be mistakenly taken for the suitable. Such results cannot be compared or shared. In these cases it is accepted to speak about absence of unity of measurements.

The third of the listed above conditions defines specific requirements to accuracy of the applied methods and measuring instruments.

Search of rational forms and methods of ensuring unity of measurements is conducted long ago. So, at the end 60-h-the beginning of the 70th the basic principles and provisions of ensuring unity of measurements were developed, the complex of the state standards regulating these principles and provisions within the State system of ensuring unity of measurements (GSI) is created.

Basis of this system was two situation "prompted" by measuring practice.

1. Accuracy of results of technical measurements can be reliable
it is estimated only on the basis of the preliminary analysis of the possible reasons and is
tochnik of errors of measurements and aprioristic assessment of these values pog
reshnost. After results of measurements are received, to estimate them
real accuracy it is not possible.

Therefore, for ensuring unity of measurements it is necessary to create and regulate such rules of preparation and carrying out measurements, processings and registrations of their results which observance guarantees a certain accuracy of all of the measurements which are carried out by these rules.

2. Before creation and introduction of GSI by the main and in essence measuring instruments (measures and measuring devices) were the only object of activity of metrological service. However the real accuracy of technical measurements was increasingly caused not by the tool, but methodical errors connected with introduction of indirect methods of measurements, toughening of conditions of use of devices, dynamic properties of objects of measurements, etc.

Therefore, ensuring unity of measurements required inclusion in a field of activity of metrological service of processes and results of measurements. Thus the traditional tasks connected with ensuring uniformity of measuring instruments entered a complex of tasks of ensuring unity of measurements which includes establishment and development:

units of the measured sizes (parameters) allowed to application;

methods and means of reproduction and storage of the sizes of units of the measured sizes (parameters);

methods and transmission media of the sizes of units from standards to working measuring instruments;

test methods and checking of measuring instruments;

nomenclatures, principles of rationing, assessment and control of metrological characteristics of measuring instruments;

forms of expression of results and indicators of accuracy of measurements;

methods of calculation of indicators of accuracy of techniques of performance of measurements;

principles of certification of techniques of performance of measurements.

The general rules of the solution of the specified tasks and> were regulated by the GSI fundamental standards which in turn served as basis for development of a large number of the state and industry standards, other normative documents of GSI concretizing requirements, norms, rules of ensuring unity of measurements in relation to separate types and areas of measurements, types of measuring instruments to branch and production specifics of separate branches of a national economy.

It should be noted that practical activities according to the accuracy of results of measurements (being guided by the corresponding regulated rules) are carried out by groups of experts (technologists, designers, - operators) which plan and directly carry out measurements. Bodies of metrological service, solving the problems stated above, create necessary conditions (Gosstandart of the USSR and its organization — at the interindustry level; bodies of departmental metrological services — at the level of departments, the enterprises and the organizations) for the correct and uniform estimates of accuracy of the "made" and used measuring information. For realization of these conditions bodies of metrological service have to aim activity of departments, enterprises and organizations at providing unity of measurements (the analysis, forecasting, planning, an assessment and rationing), to control its results, to provide systematic increase of its efficiency and compliance to modern and perspective requirements of a national economy.

Thus, on the basis of achievements of metrological science rules of metrological preparation and performance of measurements, processings and registrations of their results are developed. Implementation of metrological rules which obligation is established by normative and technical documents GSI, provides the guaranteed accuracy of results of measurements. Full, high-quality and universal implementation of these rules is provided and controlled by bodies of metrological service. Control of activities for ensuring unity of measurements in country scales (at the interindustry level) is exercised by Gosstandart of the USSR and its organization.

Lecture 4