Means of measurement, metrological characteristics. Basic directions of metrology

Significant role in the economy of any state is played by metrological standards, through which the physical parameters of various objects are measured. For this, measuring instruments are used, the application of which is regulated by separate provisions of the legislation. What is the specificity of the regulation of metrology in Russia? What norms of law characterize the approval and application of metrological measurements?

What is metrology?

To begin with, we will study some theoretical aspects that reflect the peculiarities of metrology. Means of measurement, metrological characteristics - terms related to this scientific branch.

The main directions of metrology:

- The theory of measurements;

- application of physical quantities;

- the problem of determining the accuracy of certain measurements, as well as finding a uniformity in the approaches to them;

- selection of standards and samples, as well as their practical implementation in various areas of the economy.

The main subject of studying the discipline in question is the methods and tools that are used to account for certain objects, based on their mass, length, volume, power, etc.

Basic concepts used in metrology:

- physical parameter (representing the property of an object that distinguishes it according to certain criteria from others, even if they are sufficiently similar to it);

- Measurement (a procedure that involves finding a specific value for a physical parameter through the use of various tools and when compared with standard values);

- Means of measurement and control - tools that are used to measure a particular unit of a physical parameter.

Speaking specifically about the means of measurement, it can be noted that these can be represented in several varieties. Let us consider them in more detail.

Classification

In the general case, a measurement tool is understood as a technical tool used for measuring certain objects that has normalized metrological parameters, is adapted to the reproduction or storage of certain physical parameters, the value of which is assumed to be constant within the established time interval.

It can be noted that the approval of the type of measuring instruments in Russia is carried out at the level of federal authorities, such as the Federal Agency for Technical Regulation and Metrology. What are the features of its classification? Means of measurement (metrological characteristics are also closely related to this term) can be represented, in particular:

- a measure (as a means that is used to reproduce physical parameters of a particular size);

- the device (as a means, which is used to generate a certain signal from the measurement data in a user-friendly form);

- a converter (as a means used to generate a signal from measurement data, which is to be transferred to further processing within the framework of the infrastructure involved);

- measuring system (as a combination of means used to generate measurement signals in the required format, including user).

Another criterion for the classification of measuring instruments is the level of their automation. So, they are:

- Automatic;

- partially automated;

- by hand.

Metrological means of measurement can also be classified based on their standardization. So, they can be:

- standardized;

- unregulated.

Another criterion for the classification of measuring instruments is functionality within the verification scheme. So, they can be:

- standards;

- working tools.

Another important criterion for measuring instruments is the significance of the measured parameter. Proceeding from the indicated criterion, they can be:

- the main ones;

- auxiliary ones.

In the first case, a physical parameter is measured, which is important from the point of view of the successful solution of the measurement problem. In turn, there are means of measurement, the metrological characteristics of which assume the measurement of only those parameters that have a limited impact, but nevertheless important and requiring consideration.

Let us now consider the essence of the metrological characteristics of the instruments under consideration. One of the sources of data for us will be GOST, regulating the use of the relevant infrastructure.

Metrological characteristics of measurement instruments

In accordance with state standards regulating how metering devices should be used, metrological characteristics are technical parameters that describe the properties of the relevant instruments, as well as influencing the results of certain measurements conducted to assess their quality, as well as in For the correct determination of their results.

The characteristics in question can be normalized or experimental. The first are fixed in the normative documentation. For example, the one that is included in the state register of measuring instruments, which is being formed by VNIIMS. The latter are used in a specific situation, taking into account the characteristics of the production process or the environment in which the measurements are taken.

Features of the register of measuring instruments

It will be useful to consider in more detail what is the state register of measurement instruments. This resource is included in the Federal Information Fund and is used to register those decisions approved by Rosstandart. The register of measuring instruments consists of sections in which information is reflected:

- on instruments approved by Rosstandart, certificates on the introduction of measuring instruments;

- Specific copies of instruments approved by Rosstandart;

- accredited state centers, in which tests of measuring instruments are conducted.

The purpose of keeping the register

The register under review is conducted for the following purposes:

- Accounting of measurement instruments;

- the formation of centralized funds of information on relevant decisions that are allowed to be issued by Russian enterprises, as well as to application in various economic areas;

- registration of accredited institutions engaged in testing of measurement instruments;

- registration of issued certificates on the introduction of measuring instruments, as well as certificates of accredited institutions involved in testing,

- recording of test programs for measuring instruments;

- Informational support of citizens, organizations, as well as national metrological institutions of the states participating in cooperation on the issues of recognition of tests and implementation of measuring instruments.

Registry contents

For each type of instrument, information about which is reflected in the Register, are recorded:

- name;

- registration number;

- Destination;

- Manufacturer country;

- manufacturer;

- the name of the testing center;

- validity period of the certificate;

- information on the interval between verification;

- information on the verification procedure.

The approval of a specific type of measuring instrument is carried out by Rosstandart on the basis of the results of tests of the relevant instruments carried out by specialized state centers.

If we talk about the role of the state in the regulation of the use of the tools in question and how to supplement the state register of measuring instruments that VNIIMS creates, from the point of view of rationing the work of specialists conducting research into physical parameters in certain spheres, one can pay attention to such directions Activity of state structures, as verification and certification of the measurement infrastructure. Let's study this aspect in more detail.

Verification of measurement instruments

So, along with such activities as, for example, the approval of the type of measuring instruments, the state is actively working to regulate their use. In particular, in such a direction as verification. Its implementation is regulated by a separate federal law.

In accordance with its provisions verification of measurement instruments in a number of cases is mandatory. So, for example, state measuring instruments before direct operation, as well as during their repair, should be checked - within the framework of a primary or periodic event of the appropriate type.

The task of the users of these tools is to perform a timely check. In principle, economic entities have the right to conduct it independently, but only under one condition - the availability of accreditation for activities in the field of ensuring the unity of technical measurements. In some cases, a metrological service that is accredited must carry out verification. As a rule, this applies to cases when the government of the Russian Federation defines a specific list of measurement instruments for which verification should be carried out according to the appropriate scheme.

After the procedure under review is carried out, a certificate of its implementation is issued. Competent government departments can develop special verification marks, as well as the structure of the relevant document. In addition, some government agencies may be authorized to collect the results of the verification of various measuring instruments.

In some cases, even if a particular instrument is not included in the list of measuring instruments for which verification is mandatory, a user of such an infrastructure can conduct the procedure voluntarily.

Certification of measurement instruments

As part of the state regulation of the use of various measuring instruments, certification of this infrastructure is also carried out. Its essence is in confirming first of all the security of using this or that device. In addition, a certified instrument is included in the state register of measuring instruments. As a rule, the procedure in question involves the design of:

- a certificate in accordance with GOST R or a declaration of conformity of the GOST R instrument;

- certificate on the type of measurement tools.

Certification can be carried out in Rosstandart or in one of the accredited centers. Certification is a procedure that, like verification, can be mandatory for certain measurement instruments. As a rule, such requirements are established for measuring instruments that are used in the following areas:

- the activities of the armed forces of the state;

- medicine;

- activity of power structures;

- cartography;

- geodesy;

- the sphere of regulation of the implementation of the uniformity of measurements.

Approval of measurement tools

It will be useful to consider such an aspect of the application of the instruments in question as the approval of measuring instruments. This procedure is also carried out with the participation of the state as part of metrological control. Approval of a type of measuring instrument is carried out by a competent metrological service. In this case, the following are established:

- methods for verifying the characteristics of the measuring instrument;

- Specific indicators of accuracy in measuring quantities;

- the optimum intervals for the verification of the tool.

Upon approval of the measuring instrument, the competent authority issues a special document. This is a source, such as a certificate of approval of measuring instruments. It can be designed for a single device, and for the serial release of appropriate solutions.

The condition for obtaining the second type of document may be the manufacturer's compliance with certain technical conditions. In order to issue a certificate of measuring instruments, it is also necessary to develop special documentation for the operation of the instrument. If we talk about a document for serial production of solutions, it is issued by the competent authorities for 5 years. After that, it may be renewed on the basis of a request from the manufacturer. In turn, if the certificate is issued for a single product, then its validity corresponds to the period of service of the device.

Calibration of measurement instruments

Another important aspect of state regulation of the sphere of metrology is the legal acts regulating how calibration of measuring instruments should be carried out. What does this term mean?

Calibration of measurement instruments is a procedure carried out for the purpose of determining, as well as confirming the actual values by metrological characteristics, and also the suitability of the measurement instrument for use. The main difference between calibration and verification is that the procedure under consideration is implemented primarily with respect to those measuring instruments that are not subject to control and supervision by state bodies.

In accordance with the legislation of the Russian Federation, those instruments that are not applied in the field of state regulation while ensuring the uniformity of measurements can be calibrated voluntarily. This procedure is carried out using different standards, which are compared with state primary standards or, if they are not available, with national standards that are accepted in foreign countries.

Individuals can be calibrated - business entities and individual entrepreneurs, subject to voluntary accreditation. The results of this procedure can be subsequently used in the verification of certain measuring instruments in the manner determined by the Russian government. Thus, in spite of the fact that calibration of measuring instruments is carried out voluntarily, the state nevertheless can prescribe the regulations that determine the conduct of this procedure, as well as the application of its results.