By the method of obtaining the measurement result

By the way the measurement results are presented

By the nature of the change in time of the measured PV

Accuracy characteristic

By the number of measurements

- one-time(measurements are performed once);

- multiple(a series of multiple measurements of PV of the same size)

-equal(a series of measurements of any quantity, performed with the same SI accuracy under the same conditions and with the same thoroughness);

- unequal(a series of measurements of any quantity, performed with different SI accuracy and under different conditions).

- static;

- dynamic.

- absolute(measurement of a value in its units);

- relative(measurement of changes in the value in relation to the value of the same name, taken as the original). All other things being equal, relative measurements can be performed more accurately than absolute ones, since the total error does not include the error of the measure of magnitude.

- straight(the desired PV value is obtained directly from the experimental data).

- indirect- determination of the desired value of a physical quantity based on the results of direct measurements of other physical quantities functionally related to the desired quantity. In this case, the numerical value of the desired value is found by calculation. Indirect measurements, in turn, are divided into aggregate and joint.

Aggregate measurements- simultaneous measurements of several quantities of the same name, in which the required measurements of quantities are determined by solving a system of equations obtained by measuring these quantities in various combinations.

Joint measurements- simultaneous measurements of two or more non-identical quantities to determine the relationship between them. The numerical values ​​of the desired quantities, as in the case of aggregate measurements, are found from a system of equations connecting the values ​​of the sought quantities with the value of quantities measured in a direct (or indirect) way. The number of equations should not be less number required quantities.

Measurement is a complex process and the following characteristics are important for it: principle and method of measurements, result, error, accuracy, repeatability, reproducibility, correctness and reliability.

Measuring principle- a physical phenomenon or effect underlying the measurements.

Method of measurement- reception or a set of methods for comparing the measured physical quantity with its unit in accordance with the implemented measurement principle.

Measurement result- the value of a quantity obtained by measuring it.

Measurement error- deviation of the measurement result from the true (valid) value of the measured value.

Measurement accuracy- one of the characteristics of the quality of measurements, reflecting the proximity to zero of the error of the measurement result. High measurement accuracy corresponds to small errors. Quantitatively, the accuracy is estimated by the reciprocal of the modulus of the relative error, for example, if the relative error is 0.01, then the accuracy is 100.

Measurement repeatability- the proximity to each other of the results of measurements of the same quantity, performed repeatedly by the same means, by the same method under the same conditions and with the same care. Measurement convergence reflects the effect of random errors on the measurement result.

Reproducibility- the proximity of the results of measurements of the same value, obtained in different places, by different methods and means, by different operators, at different times, but brought to the same conditions (temperature, pressure, humidity, etc.).

Right- characteristic of the quality of measurements, reflecting the closeness to zero of systematic errors in their results.

Credibility- characteristic of the quality of measurements, reflecting confidence in their results, which is determined by the probability (confidence level) that the true value of the measured quantity is within the specified limits (confidence level). Measurements are divided into reliable and unreliable, depending on how known the probabilistic characteristics of their deviation from the actual value of the measured values.

Question number 5

The importance of metrology for scientific and technological progress and in the development of the country's economy. The main tasks and problems of metrology.

As already noted, in practical life a person deals with measurements everywhere. At every step, measurements of such quantities as length, volume, weight, time, and others are found and have been known since time immemorial.

The value of measurements in modern society... They serve not only as the basis of scientific and technical knowledge, but are of paramount importance for accounting for material resources and planning, for domestic and foreign trade, for ensuring product quality, interchangeability of units and parts and improving technology, for ensuring labor safety and other types of human activity.

Metrology has great importance for the progress of natural and technical sciences, since increasing the accuracy of measurements is one of the means of improving the ways of knowledge of nature by man, discoveries and practical application of exact knowledge.

To ensure scientific and technological progress, metrology must outstrip other areas of science and technology, because for each of them accurate measurements are one of the main ways of their improvement.

The acceleration of scientific and technological progress is in direct connection with the intensive development of metrology and precision measurement technology, which are necessary both for the development of natural and exact sciences and for the creation of new technology and improvement of technical control and management tools. All this poses a number of important tasks for metrology.

In the field of measurement units, one of the main tasks is to unify them on the basis of the widespread introduction of a single International System of Units (SI). This system ensures uniformity of the applied units for all fields of science and technology. The requirements for the top echelon in measuring instruments - for standards - are significantly increased. The accuracy of measurements in industry in many cases approaches the maximum possible for a given state of technology and, consequently, the accuracy of the standards themselves. The next day is the increasingly widespread use of fundamental physical constants and atomic constants, characterized by high stability, as the basis for new, more perfect standards.

To maintain the uniformity of measurements carried out in different places and at different times, it is necessary to ensure the transfer of the size of units from the standards to the working measuring instruments with the least loss of accuracy. The device of modern standards and methods of transferring the size of units must ensure that this requirement is met.

An urgent task is to extend accurate measurements to areas of very small and large values ​​of the measured quantities (small and large masses, deep vacuum and ultrahigh pressures, ultralow and ultrahigh temperatures, ultrahigh frequencies, etc.). The need to transfer the size of units of measurement to instruments measuring vanishingly small or very large values ​​of quantities often does not allow one to be limited to one standard and requires the creation of several independent special standards for the same quantity.

The issues of carrying out extremely accurate measurements under special non-stationary conditions, under dynamic modes, at high accelerations, high or very low temperatures, pressures, and frequencies also acquire great importance.

The development of measuring and measuring-control systems has led to qualitative changes in the measurement process itself. In addition to quantities, processes that have numerous parameters and characteristics are compared. Metrological support should be extended to measuring and control systems.

There are also important tasks in the field of measurement theory. The development of mathematical statistics and the theory of random functions influences the issues of metrological processing of measurement results.

Wide application automatic methods of control and regulation require additions to the established metrological concepts and concepts. Methods and measuring instruments used in medicine, construction, chemical industry and other branches of science and technology must be improved.

Serving scientific basis measuring technology, metrology must ensure the necessary reliability and correctness of the received measuring information, as well as legally determine the uniformity of measurements in the country, the uniformity of methods for controlling technological processes and product testing. Metrology both summarizes practical experience in this area and accordingly guides the development of measuring technology.

Metrology is organically related to standardization, and this connection is expressed primarily in the standardization of units of measurement, the system of state standards, measuring instruments and verification methods, in the creation of standard samples of the properties and composition of a substance. In turn, standardization is based on metrology, which ensures the correctness and comparability of test results for materials and products, and also borrows from metrology methods for determining and controlling quality indicators.

In close interaction, metrology and standardization are important levers of technical progress in all areas of science and economy of the country.

Currently, there are many types of measurements, distinguished by the physical nature of the measured value and factors that determine various conditions and measurement modes. The main types of measurements of physical quantities, including linear-angular (GOST 16263-70), are straight, indirect, cumulative, joint, absolute and relative.

Most widely used direct measurements , consisting in the fact that the desired value of the measured quantity is found from experimental data using measuring instruments. The linear dimension can be set directly on the scales of a ruler, tape measure, caliper, micrometer, effective force - with a dynamometer, temperature - with a thermometer, etc.

The equation for direct measurements is:

where Q is the required value of the measured value; X is the value of the measured quantity obtained directly from the readings of the measuring instruments.

Indirect- such measurements in which the desired value is determined by the known relationship between this value and other values ​​obtained by direct measurements.

The indirect measurement equation is:

Q = f (x 1, x 2, x 3, ...),

where Q is the desired value of the indirectly measured value; x 1, x 2, x 3, ... are the values ​​of quantities measured by direct measurements.

Indirect measurements are used in cases where the required value is impossible or very difficult to measure directly, i.e. direct measurement, or when direct measurement is less accurate.

Examples of an indirect type of measurement are establishing the volume of a parallelepiped by multiplying three linear quantities (length, height and width) determined using the direct type of measurement, calculating engine power, determining the resistivity of a conductor by its resistance, length and area cross section etc.

An example of an indirect measurement is also the measurement of the average diameter of an external fastening thread using the "three wire" method. This method is based on the most accurate determination of the average thread diameter d 2 as the diameter of a conditional cylinder, the generatrix of which divides the thread profile into equal parts P / 2 (Fig.2.1):

where D meas - distance, including wire diameters, obtained by direct measurements;

d 2 - the diameter of the wire, providing contact with the thread profile at points lying on the generatrix d 2;

α is the angle of the thread profile;

P - thread pitch.

Aggregate measurements carry out the simultaneous measurement of several quantities of the same name, at which the desired value is found by solving the system of equations obtained by direct measurements of various combinations of these quantities. An example of cumulative measurements is the calibration of the set weights by the known mass of one of them and by the results of direct comparisons of the masses of various combinations of weights.

For example, you need to calibrate a burn of mass 1; 2; 5; 10 and 20 kg. The exemplary weight is 1 kg, designated 1 vol.

Let's take measurements, changing the combination of weights each time:

1 = 1 06 + a; 1 + l about = 2 + b; 2 = 2 + with; 1+2 + 2 = 5 + d etc.

Letters a, b, with, d- unknown values ​​of the weights that have to be added or subtracted from the weight of the weight. Having solved the system of equations, you can determine the value of each weight.

Joint measurements- simultaneous measurements of two or more non-identical quantities to find the relationship between them, for example, measurements of the volume of a body, made with measurements of different temperatures, causing a change in the volume of this body.

The main types of measurements, based on the nature of the measurement results for a variety of physical quantities, include absolute and relative measurements.

Absolute measurements based on direct measurements of one or more physical quantities. An example of an absolute measurement is measuring the diameter or length of a roller with a vernier caliper or micrometer, or measuring temperature with a thermometer.

Absolute measurements are accompanied by an assessment of the entire measured value.

Relative measurements based on the measurement of the ratio of the measured quantity, which plays the role of a unit, or the measurement of the quantity in relation to the quantity of the same name, taken as the initial one. As samples, exemplary measures in the form of plane-parallel gage blocks are often used.

An example of relative measurements can serve as measurements of the calibers of plugs and staples on horizontal and vertical optimometers with the setting of measuring instruments according to exemplary measures. When using reference standards or reference parts, relative measurements can improve the accuracy of the measurement results compared to absolute measurements.

In addition to the considered types of measurement according to the main criterion - the method of obtaining the measurement result, the types of measurements are also classified according to the accuracy of the measurement results - by equal and unequal, according to the number of measurements - by multiple and one-time, in relation to the change in the measured value over time - by static and dynamic, by the presence of contact of the measuring surface of the measuring instrument with the surface of the product - on contact and contactless and etc.

Depending on the metrological purpose, measurements are divided into technical- production measurements, control and calibration and metrological- measurements with the utmost possible accuracy using standards in order to reproduce units of physical quantities to transfer their size to working measuring instruments.

Measurement methods

In accordance with RMG 29–99, the main measurement methods include the method of direct assessment and comparison methods: differential, zero, substitution and coincidence.

Direct method- a measurement method in which the value of a quantity is determined directly from the reading device of a direct-acting measuring device, for example, measuring the shaft with a micrometer and force - with a mechanical dynamometer.

Comparison Methods with Measure- methods in which a measurand is compared with a reproducible measure:

differential method characterized by the measurement of the difference between the measured value and the known value reproduced by the measure. An example of a differential method is the measurement of the difference between two voltages with a voltmeter, one of which is known with great accuracy, and the other is the desired value;

null method- at which the difference between the measured value and the measure is reduced to zero. In this case, the zero method has the advantage that the measure can be many times smaller than the measured value, for example, weighing on a scale, when there is a weighed load on one shoulder, and a set of reference weights on the other;

substitution method- a method of comparison with a measure, in which a measured value is replaced by a known value, a reproducible measure. The substitution method is used when weighing with alternately placing the measured mass and weights on the same pan;

coincidence method- a method of comparison with a measure, in which the difference between the measured value and the value reproduced by the measure is measured using the coincidence of the scale marks or periodic signals. An example of using this method is measuring length with a vernier caliper.

Depending on the type of measuring instruments used, there are instrumental, expert, heuristic and organoleptic measurement methods.

Instrumental method based on the use of special technical means, including automated and automatic.

Expert method estimates are based on the judgment of a team of experts.

Heuristic methods estimates are based on intuition.

Organoleptic methods estimates are based on the use of human senses. Assessment of the state of an object can be carried out by element-by-element and complex measurements. The element-by-element method is characterized by the measurement of each parameter of the product separately. For example, eccentricity, ovality, cutting of a cylindrical shaft. The complex method is characterized by the measurement of the total quality indicator, which is influenced by its individual components. For example, measuring the radial runout of a cylindrical part, which is affected by eccentricity, ovality, etc.; control of the position of the profile along the limiting contours, etc.

INTRODUCTION …………………………………………………………… .3
1. Question 1 ………………………………………………………… ... 4
2. Question 2 ………………………………………………………… ... 8
3. Question 3 ………………………………………………………… .12
4. Question 4 ………………………………………………………… .15
5. Question 5 ………………………………………………………… .16
List of used literature ………………………………… ..20

1. Concept and classification of measurements. a brief description of basic types of measurements.

Measurement - a set of operations for determining the ratio of one (measured) quantity to another homogeneous quantity, taken as a unit stored in a technical means (measuring instrument). The resulting value is called the numerical value of the measured quantity, the numerical value together with the designation of the unit used is called the value of the physical quantity. The measurement of a physical quantity empirically is carried out using various measuring instruments - measures, measuring instruments, measuring transducers, systems, installations, and so on. Measurement of a physical quantity includes several stages:
1) comparison of the measured value with the unit;
2) transformation into a form that is convenient for use (various methods of indication).
The measurement principle is a physical phenomenon (effect) underlying measurements.
A measurement method is a reception or a set of methods for comparing a measured physical quantity with its unit in accordance with the implemented measurement principle. The measurement method is usually determined by the design of the measuring instrument.
The characteristic of the measurement accuracy is its error or uncertainty. Measurement examples:
In the simplest case, by applying a ruler with divisions to any part, in fact, its size is compared with the unit stored by the ruler, and, after counting, the value of the quantity (length, height, thickness and other parameters of the part) is obtained.
Using a measuring device, the size of the value converted into the movement of the pointer is compared with the unit stored by the scale of this device, and the count is carried out.
In cases where it is impossible to carry out a measurement (the quantity is not highlighted as a physical one, or the unit of measurement of this quantity is not defined), it is practiced to evaluate such quantities according to conventional scales, for example, the Richter scale of earthquake intensity, the Mohs scale - the hardness scale of minerals.
A science that studies all aspects of measurement is called "Metrology".
1.1. Measurement classification.
1. By types of measurements:
a) Direct measurement - measurement in which the desired value of a physical quantity is obtained directly.
b) Indirect measurement - determination of the desired value of a physical quantity based on the results of direct measurements of other physical quantities functionally related to the desired quantity.
c) Joint measurements - simultaneous measurements of two or more not of the same name to determine the relationship between them.
d) Aggregate measurements - simultaneous measurements of several quantities of the same name, in which the desired values ​​of quantities are determined by solving a system of equations obtained by measuring these quantities in various combinations.
e) Redundant measurements - measurements of several series of homogeneous physical quantities, the dimensions of which are related to each other according to the law of arithmetic or geometric progression, with unchanged or normalized changed values ​​of the parameters of the nonlinear (in the general case) transformation function of the sensor (or the measuring channel as a whole), at which the desired value of the physical quantity is obtained reduced to the input of the measuring channel by processing the results of intermediate measurements according to the equation of redundant measurements, that is, indirectly.
Aggregate measurements are a special case of redundant measurements. Redundant measurements provide automatic (natural) elimination of systematic components of the error of the final measurement result.
2. By measurement methods:
a) Direct assessment method - a measurement method in which the value of a quantity is determined directly from an indicating measuring instrument.
b) Comparison method with a measure - a measurement method in which the measured value is compared with the value reproduced by the measure.
c) Zero measurement method - a method of comparison with a measure, in which the resulting effect of the influence of the measured value and the measure on the comparison device is brought to zero.
d) Method of measurement by substitution - a method of comparison with a measure, in which the measured value is replaced by a measure with a known value of the quantity.
e) Addition measurement method - a method of comparison with a measure, in which the value of the measured quantity is supplemented by a measure of the same quantity so that the comparison device is affected by their sum equal to a predetermined value.
f) Differential measurement method - a measurement method in which the measured quantity is compared with a homogeneous quantity having a known value that slightly differs from the value of the measured quantity, and in which the difference between these two quantities is measured.
3. According to the conditions that determine the accuracy of the result:
Metrological measurements - measurements of the highest possible accuracy achievable with existing level technology. This class includes all high-precision measurements and, first of all, reference measurements associated with the highest possible accuracy of reproduction of the established units of physical quantities. This also includes measurements of physical constants, especially universal ones, for example, measurement of the absolute value of acceleration free fall.
Control and verification measurements, the error of which, with a certain probability, should not exceed a certain specified value. This class includes measurements performed by laboratories of state control (supervision) over compliance with the requirements of technical regulations, as well as the state of measuring equipment and factory measuring laboratories. These measurements guarantee the error of the result with a certain probability, not exceeding some predetermined value.
Technical measurements, in which the error of the result is determined by the characteristics of the measuring instruments. Examples of engineering measurements are measurements taken during production on industrial enterprises, in the service sector, etc.
4. Based on the measurement results:
Absolute measurement is a measurement based on direct measurements of one or more basic quantities and (or) the use of the values ​​of physical constants.
Relative measurement is a measurement of the ratio of a quantity to a quantity of the same name, which plays the role of a unit, or a measurement of the change in a quantity in relation to a quantity of the same name, which is taken as the initial one.

2. State metrological control and supervision: areas of distribution, characteristics of species. Rights and obligations of state inspectors to ensure the uniformity of measurements. Responsibility for violation of metrological rules.

State metrological control and supervision is carried out by the State Metrological Service of the Gosstandart of Russia.
State metrological control includes:
- type approval of measuring instruments;
- verification of measuring instruments, including standards;
- licensing of the activities of legal entities and individuals for the manufacture, repair, sale and rental of measuring instruments.
State metrological supervision is carried out:
- for the release, condition and use of measuring instruments, certified measurement procedures, standards of units of quantities, compliance with metrological rules and norms;
- for the amount of goods alienated when performing trade operations;
- for the number of prepackaged goods in packages of any kind during their packaging and sale.
State metrological control and supervision, carried out in order to verify compliance with metrological rules and norms, apply to:
- healthcare, veterinary medicine, security environment, ensuring labor safety;
- trade operations and mutual settlements between the buyer and the seller, including for operations using slot machines and devices;
- government accounting operations;
- ensuring the defense of the state;
- geodetic and hydrometeorological work;
- banking, tax, customs and postal operations;
- production of products supplied under contracts for state needs in accordance with the legislation Russian Federation;
- testing and quality control of products in order to determine compliance with the mandatory requirements of state standards of the Russian Federation;
- compulsory certification of products and services;
- measurements carried out on behalf of the court authorities, the prosecutor's office, the arbitration court, and state governing bodies of the Russian Federation;
- registration of national and international sports records.
Regulatory acts of the republics within the Russian Federation, autonomous region, autonomous regions, territories, regions, cities of Moscow and St. Petersburg, state metrological control and supervision can be extended to other areas of activity.
State metrological control and supervision is carried out by officials of Gosstandart of Russia - chief state inspectors and state inspectors for ensuring the uniformity of measurements of the Russian Federation, republics within the Russian Federation, autonomous regions, autonomous districts, territories, regions, cities of Moscow and St. Petersburg (hereinafter - state inspectors).
The implementation of state metrological control and supervision may be entrusted to state inspectors for the supervision of state standards, acting in accordance with the legislation of the Russian Federation and having passed certification as state inspectors to ensure the uniformity of measurements. State inspectors performing verification of measuring instruments are subject to certification as verifiers.
State inspectors exercising state metrological control and supervision on the relevant territory have the right, without hindrance, upon presentation of an official certificate:
- to visit facilities where measuring instruments are operated, produced, repaired, sold, maintained or stored, regardless of the subordination and forms of ownership of these facilities;
- check the correspondence of the used units of quantities to those approved for use;
- check measuring instruments, check their condition and conditions of use, as well as compliance with the approved type of measuring instruments;
- check the application of certified measurement procedures, the state of the standards used to verify measuring instruments;
- check the number of goods alienated when performing trade operations;
- take samples of products and goods, as well as prepackaged goods in packages of any kind for supervision;
- use technical means and involve the personnel of the facility subject to state metrological control and supervision.
If violations of metrological rules and norms are detected, the state inspector has the right:
- prohibit the use and release of measuring instruments of unapproved types or those that do not correspond to the approved type, as well as unauthorized ones;
- cancel the verification certificate in cases when the measuring instrument gives incorrect readings or the verification interval is overdue;
- if necessary, withdraw the measuring instrument from operation;
- submit proposals for the cancellation of licenses for the manufacture, repair, sale and rental of measuring instruments in cases of violation of the requirements for these types of activities;
- give binding instructions and establish deadlines for eliminating violations of metrological rules and norms;
- draw up protocols on violation of metrological rules and norms.

2.1 Responsibility of government inspectors.
State inspectors exercising state metrological control and supervision are obliged to strictly comply with the legislation of the Russian Federation, as well as the provisions of regulatory documents on ensuring the uniformity of measurements and state metrological control and supervision.
For non-fulfillment or improper fulfillment of official duties, excess of powers and for other violations, including disclosure of state or commercial secrets, state inspectors may be held liable in accordance with the legislation of the Russian Federation.
Complaints about the actions of state inspectors are submitted within 20 days from the date of their decision to the body of the State Metrological Service to which they are directly subordinate, or to a higher authority. Complaints are considered and decisions on them are made within a month from the date of filing the complaint.
Actions of state inspectors can also be appealed against in court in accordance with the established procedure.
Appealing against the actions of state inspectors does not suspend the implementation of their instructions.
Legal entities and individuals, as well as state governing bodies of the Russian Federation, guilty of violating the provisions of the Law "On ensuring the uniformity of measurements", in accordance with the current legislation, bear criminal, administrative or civil liability

3. State control and supervision over compliance with the mandatory requirements of technical regulations and state standards. Rights, duties and responsibilities of state inspectors.

State control and supervision over compliance by business entities with the mandatory requirements of state standards is carried out at the stages of development, preparation of products for production, their manufacture, sale (supply, sale), use (operation), storage, transportation and disposal, as well as during the performance of work and the provision of services.
The procedure for exercising state control and supervision over compliance with the mandatory requirements of state standards is established by the State Standard of Russia in accordance with the legislation of the Russian Federation.
Officials of business entities are obliged to create all conditions necessary for the implementation of state control and supervision.
The bodies exercising state control and supervision over compliance with the mandatory requirements of state standards are Gosstandart of Russia, other specially authorized state management bodies within their competence.
The implementation of state control and supervision over compliance with the mandatory requirements of state standards is carried out by officials of state governing bodies within their competence.
Direct implementation of state control and supervision over compliance with the mandatory requirements of state standards on behalf of the Gosstandart of Russia is carried out by its officials - state inspectors:
chief state inspector of the Russian Federation for supervision of state standards;
chief state inspectors of the republics within the Russian Federation, territories, regions, autonomous regions, autonomous districts, cities for the supervision of state standards;
state inspectors for the supervision of state standards.
State inspectors exercising state control and supervision over compliance with the mandatory requirements of state standards are representatives of state governing bodies and are under the protection of the state.
The state inspector has the right:
free access to office and production premises of a business entity;
receive from a business entity documents and information necessary for state control and supervision;
use technical means and specialists of a business entity during state control and supervision;
to carry out, in accordance with the current regulatory documents on standardization, sampling and samples of products and services to control their compliance with the mandatory requirements of state standards with the attribution of the cost of consumed samples and the cost of testing (analyzes, measurements) to the production costs of the inspected business entities;
issue orders to eliminate the identified violations of mandatory requirements of state standards at the stages of development, preparation of products for production, manufacture, sale (supply, sale), use (operation), storage, transportation and disposal, as well as during the performance of work and provision of services;
issue orders to prohibit or suspend the sale (supply, sale), use (operation) of proven products, as well as the performance of work and the provision of services in cases of non-compliance of products, works and services with the mandatory requirements of state standards;
prohibit the sale of products, the performance of work and the provision of services in the event that a business entity evades the presentation of products, works and services for inspection.
The chief state inspector of the Russian Federation for the supervision of state standards, the chief state inspectors of the republics within the Russian Federation, territories, regions, autonomous regions, autonomous districts, cities for the supervision of state standards have the right to issue to a business entity the instructions specified in paragraphs seven and eight of this paragraph, and also have the right:
to adopt resolutions on the application of fines to business entities for violations of the mandatory requirements of state standards;
prohibit the sale of imported products and the provision of import services that do not meet the mandatory requirements of state standards and have not passed state registration in accordance with the legislation of the Russian Federation.
State inspectors, in case of non-fulfillment of the orders and decisions issued by them, by business entities shall send the necessary materials to the arbitration court, prosecutor's office or the court for taking measures established by the legislation of the Russian Federation.
State inspectors, when carrying out their duties, must protect the interests of consumers, business entities and the state, guided by legislation.
State inspectors bear responsibility established by law for non-fulfillment and improper fulfillment of the duties assigned to them, disclosure of state or commercial secrets.

DELA OJSC received reliable information that the batch of frozen semi-finished products supplied by Sokolov and Co does not meet the requirements of technical regulations. Director of OJSC "DELA" withdrew these products from sale, delivered them to the manufacturer with his own transport for the purpose of return. In addition, the buyer demanded compensation for the value of the goods and reimbursement of shipping costs. To which he was refused. Assess the legality of the actions of the parties. Confirm the answer by the article of the law.

The consumer, in the event that defects are found in the goods, if they have not been agreed by the seller, at his choice has the right to:
demand replacement for goods of the same brand (of the same model and (or) article);
demand replacement for the same product of another brand (model, article) with a corresponding recalculation of the purchase price;
demand a commensurate reduction in the purchase price; demand the immediate gratuitous elimination of defects in the goods or reimbursement of expenses for their correction by the consumer or a third party;
refuse to fulfill the contract of sale and demand the return of the amount paid for the goods. At the request of the seller and at his expense, the consumer must return the defective product.
At the same time, the consumer has the right to demand also full compensation for losses caused to him as a result of the sale of goods of inadequate quality. Losses are reimbursed within the time frame established by this Law to meet the relevant consumer requirements.

5. To ensure the technological process in public catering establishments, various technical measuring instruments are used. As the person responsible for the condition and use of weighing equipment in the enterprise, indicate the place of installation of the verification mark on the weights and dial table scales. Explain what documents confirm the suitability of measuring instruments for use What document is drawn up in enterprises to ensure the timely verification of measuring instruments The procedure for its preparation. Copies required documents attach.

Verification of measuring instruments - a set of operations performed by the bodies of the State Metrological Service (HMS bodies) or other authorized bodies and organizations in order to determine and confirm the compliance of measuring instruments with the established technical requirements... In accordance with the Law of the Russian Federation "On Ensuring the Uniformity of Measurements", measuring instruments subject to state metrological control and supervision are subject to verification upon release from production or repair, upon import by import and operation. Sale of only verified measuring instruments is allowed. The result of verification is a confirmation of the suitability of measuring instruments for use or recognition of a measuring instrument as unsuitable for use. If a measuring instrument according to the results of verification is recognized as suitable for use, then an imprint of a verification mark is applied to it and (or) technical documentation and (or) a “Certificate of verification” is issued. If, according to the results of verification, the measuring instrument is recognized as unsuitable for use, the imprint of the verification mark and (or) "Certificate of verification" are canceled and a "Notice of unsuitability" is issued or a corresponding entry is made in the technical documentation.
Positive results of state and departmental primary and periodic checks are drawn up by:
a) when the scales are released from production - by an entry in the passport (operating manual) of the manufacturer, certified by the verifier with an imprint of the verification mark;
b) in case of periodic departmental verification - by a mark in a document drawn up by the departmental metrological service and agreed with the State Standard;
c) upon release from production of scales supplied assembled after repair and at the place of operation - by applying an imprint of a stamp, depending on the type of scales and their design features, on:
main scale plug; fixing plug of the main weight, plugs of the additional scale and weight; anchor plug of the transmission arm; fastening plugs of the struts holding the calibration weight of the rocker indicator, if the stacks have a device that allows you to change the position of the center of gravity of the rocker arm, for scales with a rocker indicator;
fixing plugs of built-in weights of the balance intermediate mechanism; dial index and discrete reading device seals on both sides; transmission lever slide - for scales with dial indicator and discrete reading device;
fixing plugs of built-in weights of the balance intermediate mechanism; projection pointer screws; transmission lever skids - for scales with a projection indicator;
the seals of the force-measuring sensor and the scale division regulator on the indicating device - for electromechanical scales;
removable cups, blind plug, pressed into the main arm of an open-mechanism weight scale;
removable cups, sealing wax, poured into a special device, mounted on the casing of a weight scale with a closed mechanism;
a plug pressed into the rocker arm, as well as a plug that closes the adjusting cavity of the movable weight - for steelyards.
Responsibility for the operation, storage and repair of measuring equipment in accordance with the requirements of the manufacturer's technical documentation is assigned to the heads of departments who directly use them in their work.
The development of annual schedules for state verification of measuring instruments and schedules for metrological certification of test equipment is carried out by the responsible performers for metrological support on the basis of the Lists of measuring equipment that they maintain. The form of the SI state verification schedule is given below. These schedules are signed by the responsible executors for metrological support and approved by the chief engineer of the enterprise at the end of the current year for the planned period.
Based on the schedules of the state verification of measuring instruments, submitted by the responsible executors for metrological support, the responsible for metrology, a general schedule for the enterprise for the periodic verification of measuring instruments is developed. The developed schedule for periodic verification of measuring instruments is signed by the person in charge of metrology, approved by the general director of the enterprise and submitted for approval to an accredited body (CSM).

Form of the schedule for periodic verification of measuring instruments

PERIODIC VERIFICATION SCHEDULE OF MEASUREMENTS

AGREED APPROVED
____________________ _________________
______________ ____________
_______________ 200_ _______________ 200_

P / p No.
Code
funds
measurements

Name,
type Metrological
specifications
Periodicity
verification
(months)
date
the last
verification
Place of verification
Availability of SI on 01.01.
200_y.
count
To be verified in 200_.
count including by month Note

I AM
1 f
2 m
3 a
4 m
5 and
6 and
7 a
8 sec
9 about
10 n
11 d
12
Class, category Limit
(range
measurements)

Signature

LIST OF USED LITERATURE

1. Electronic resource. Access mode:
http://ru.wikipedia.org/wiki/%C8%E7%EC%E5%F0%E5%ED%E8%E5
2. Law of the Russian Federation of April 27, 1993 No. 4871-1 "On ensuring the uniformity of measurements." Electronic resource. Access mode: http://www.femida.info/25/zo27a1993N4871Ip003.htm
3. The law of the Russian Federation of June 10, 1993. No. 5154-1 "On standardization" (as amended on December 27, 1995, December 30, 2001, July 10, 25, 2002). Electronic resource. Access mode: http://www.femida.info/26/zo10i1993N5154Ip002.htm.
4. Law "On Protection of Consumer Rights", (as amended on June 2, 1993, January 9, 1996, December 17, 1999, December 30, 2001, August 22, November 2, December 21, 2004, July 27, October 16, November 25, 2006, October 25, 2007, July 23, 2008, June 3, November 23, 2009. Electronic resource.Access mode: http://ozpp.ru/laws/zpp.php
5. GOST 8.453-82. State system for ensuring the uniformity of measurements. Scales for static weighing. Verification methods and means. Electronic resource. Access mode: http://www.complexdoc.ru/text/%D0%93%D0%9E%D0%A1%D0%A2%208.453-82

Measurement is the most important concept in metrology. This is an organized human action performed for the quantitative cognition of the properties of a physical object by empirically determining the value of any physical quantity.

There are several types of measurements. When classifying them, they usually proceed from the nature of the dependence of the measured quantity on time, the type of the measurement equation, the conditions that determine the accuracy of the measurement result and the ways of expressing these results.

By the nature of the dependence of the measured value on the time, measurements are divided into:

static, in which the measured value remains constant over time;

dynamic, during which the measured value changes and is not constant over time.

Static measurements are, for example, measurements of body size, constant pressure, dynamic - measurements of pulsating pressures, vibrations.

According to the number of measurements, they are divided into single and multiple. A single measurement is a measurement taken once. Multiple is a measurement of a physical quantity of the same size, the result of which is obtained from several successive measurements, that is, consisting of a number of single measurements. Multiple measurement is performed in the case when the random component of the error of a single measurement can exceed the value required by the conditions of the problem. By performing a series of successive individual measurements, one multiple measurement is obtained, the error of which can be reduced by methods of mathematical statistics.

According to the method of obtaining measurement results, they are divided into:

• indirect;

  cumulative;

  joint.

Straight lines are measurements in which the desired value of a physical quantity is found directly from experimental data. Direct measurements can be expressed by the formula Q = X, where Q is the desired value of the measured quantity, and X is the value directly obtained from the experimental data.

In direct measurements, the measured value is subjected to experimental operations, which is compared with the measure directly or with the help of measuring instruments calibrated in the required units. Examples of straight lines are measurements of body length with a ruler, mass using scales, etc. Direct measurements are widely used in mechanical engineering, as well as in the control of technological processes (measurement of pressure, temperature).

Indirect measurements are measurements in which the desired value is determined on the basis of the known relationship between this value and the values ​​subject to direct measurements, i.e. do not measure the quantity being determined itself, but others that are functionally related to it. The value of the measured quantity is found by calculating by the formula Q = F (x 1, x 2, ..., x n), where Q is the desired value of the indirectly measured quantity; F - functional dependence, which is known in advance, x 1, x 2, ..., x n - values ​​of quantities measured in a direct way.

Aggregate is a simultaneous measurement of several quantities of the same name, in which the desired one is determined by solving a system of equations obtained by direct measurements of various combinations of these quantities.

Joint measurements are simultaneously made measurements of two or more non-identical quantities to find relationships between them.

According to the conditions that determine the accuracy of the result, measurements are divided into three classes:

measuring the highest possible accuracy achievable with the current state of the art. Certain special measurements requiring high accuracy also belong to this class;

control and verification measurements, the error of which, with a certain probability, should not exceed a certain specified value;

technical measurements, in which the error of the result is determined by the characteristics of the measuring instruments.

According to the way of expressing the measurement results, there are absolute and relative measurements.

Absolute measurements are those that are based on direct measurements of one or more basic quantities or on the use of the values ​​of physical constants.

Measurements of the ratio of a quantity to a quantity of the same name, which plays the role of a unit, or measurement of a quantity in relation to a quantity of the same name, taken as the initial one, is called relative.

There are other classifications of measurements, for example, according to the connection with the object (contact and non-contact), according to the measurement conditions (equal and unequal).

The main characteristics of measurements are: measurement principle, measurement method, error, accuracy, correctness and reliability.

Measuring principle- a physical phenomenon or a set of physical phenomena underlying measurements. For example, measuring body weight by weighing using gravity proportional to mass, measuring temperature using the thermoelectric effect.

At present, all measurements, in accordance with the physical laws used in their conduct, are grouped into 13 types of measurements. In accordance with the classification, they were assigned two-digit codes for the types of measurements: geometric (27), mechanical (28), flow rate, capacity, level (29), pressure and vacuum (30), physicochemical (31), temperature and thermophysical (32 ), time and frequency (33), electrical and magnetic (34), radioelectronic (35), vibroacoustic (36), optical (37), parameters ionizing radiation(38), biomedical (39).

Measurement method- a set of techniques for using principles and measuring instruments.

Measurement method- reception or a set of methods for comparing the measured value with its unit in accordance with the implemented measurement principle. As a rule, the measurement method is determined by the design of the measuring instrument. Measuring instruments are used technical means with standardized metrological properties. Examples of common measurement methods are the following:

direct assessment method - a method in which the value of a quantity is determined directly by an indicating measuring instrument. For example, weighing on a dial scale or measuring pressure with a spring pressure gauge;

differential method - a measurement method in which the measured value is compared with a homogeneous value having a known value that slightly differs from the value of the measured value, and in which the difference between these two values ​​is measured. This method can give very accurate results. So, if the difference is 0.1% of the measured value and is estimated by the device with an accuracy of 1%, then the measurement accuracy of the desired value will be already 0.001%. For example, when comparing the same linear measures, where the difference between them is determined by an eyepiece micrometer, which makes it possible to estimate it to tenths of a micron;

zero measurement method - a method of comparison with a measure, in which the resulting effect of the influence of the measured value and the measure on the comparison device is brought to zero. Measure - a measuring instrument designed to reproduce and store a physical quantity. For example, measuring the mass on an equal-shoulder balance using weights. It is one of the most accurate methods.

comparison method with a measure - a measurement method in which the measured value is compared with the value reproduced by the measure. For example, measuring the DC voltage across the compensator by comparing it with the known EMF of a normal element. The measurement result with this method is either calculated as the sum of the value of the measure used for comparison and the reading of the measuring device, or is taken equal to the value of the measure. There are various modifications of this method: the method of measurement by substitution (the measured value is replaced by a measure with a known value of the quantity, for example, when weighing by alternately placing the mass and weights on the same pan) and the addition measurement method (the value of the measured measure is supplemented by the measure of the same quantity with so that the comparison device is affected by their sum equal to a predetermined value).

The quality of measurements is characterized by accuracy, reliability, correctness, repeatability and reproducibility of measurements, as well as the size of the error.

Measurement error- the difference between the obtained during measurement and the true values ​​of the measured value. The error is caused by imperfection of methods and measuring instruments, inconstancy of observation conditions, as well as insufficient experience of the observer or the peculiarities of his sense organs.

Accuracy of measurements Is a measurement characteristic reflecting the proximity of their results to the true value of the measured quantity. Quantitatively, the accuracy can be expressed as the reciprocal of the modulus of the relative error.

Measurement accuracy is defined as the quality of measurement, reflecting the closeness to zero of systematic errors of the results (i.e. such errors that remain constant or change regularly when repeated measurements of the same quantity). The correctness of measurements depends, in particular, on how much the actual size of the unit in which the measurement is performed differs from its true size (by definition), i.e. on the extent to which the measuring instruments used for this type of measurement were correct (correct).

The most important characteristic of the quality of measurements is their credibility... It characterizes confidence in the measurement results and divides them into two categories: reliable and unreliable, depending on whether the probabilistic characteristics of their deviations from the true values ​​of the corresponding quantities are known or unknown. Measurement results, the reliability of which is unknown, are of no value and in some cases can serve as a source of misinformation.

Convergence(repeatability) is the quality of measurements, reflecting the proximity to each other of the results of measurements of the same parameter, performed repeatedly with the same measuring instruments, by the same method under the same conditions and with the same accuracy.

Reproducibility- this is the quality of measurements, reflecting the proximity to each other of the results of measurements of the same parameter, carried out in different conditions (at different times, by different means, etc.).

There are several types of measurements. When classifying them, they usually proceed from the nature of the dependence of the measured quantity on time, the type of the measurement equation, the conditions that determine the accuracy of the measurement result and the ways of expressing these results.

1) By the nature of the dependence of the measured value on time:

a) static- take place when the measured value is practically constant (measurements of body size, constant pressure);

b) dynamic, associated with quantities that undergo certain changes in the measurement process (measurements of pulsating pressures, vibrations).

2) By the way you get the results:

a) Direct measurements- measurements in which the desired value of a physical quantity is found directly from experimental data by direct comparison with a measure. (measurement of pressure, temperature, etc.).

b) Indirect measurements- measurements in which the desired value is determined on the basis of a known relationship between this value and the values ​​subjected to direct measurements, i.e. do not measure the quantity being determined itself, but others that are functionally related to it. The value of the measured quantity is found through a transformation or through an established formula (determining the volume of a body by direct measurements of its geometric dimensions, finding the specific electrical resistance of a conductor by its resistance, length and cross-sectional area).

c) Aggregate measurements- these are simultaneous measurements of several quantities of the same name that characterize a given object or product, in which the desired one is determined by solving a system of equations obtained by direct measurements of various combinations of these quantities (determination of the mass of individual weights of a set (or weather forecasting based on measurements of wind strength, air humidity, fronts, etc.).

d) Joint measurements- these are simultaneous measurements of two or more inhomogeneous physical quantities to find dependencies between them (measurement of electrical resistance at certain temperature parameters and temperature coefficients of the measuring resistor according to the data of direct measurements of its resistance at different temperatures).

3) According to the conditions that determine the accuracy of the result:

a) Measurements of the highest possible accuracy, achievable with the current state of the art.

These include, first of all, reference measurements associated with the maximum possible reproduction accuracy of established units of physical quantities, and, in addition, measurements of physical constants, primarily universal ones (for example, the absolute value of the acceleration of gravity, etc.). Some special measurements that require high accuracy also belong to this class.

b) Control and verification measurements, the error of which, with a certain probability, should not exceed a certain specified value.

These include measurements performed by laboratories of state supervision over the implementation and compliance with standards and the state of measuring equipment and factory measuring laboratories, which guarantee the error of the result with a certain probability not exceeding a certain predetermined value.

c) Technical measurements, in which the error of the result is determined by the characteristics of the measuring instruments.

Examples of technical measurements are measurements carried out in the production process at machine-building enterprises, on switchboards of power plants, etc.

4 ) By the way of expressing the measurement results:

a) Absolute measurements are called that are based on direct measurements of one or more basic quantities or on the use of the values ​​of physical constants (determination of length in meters, electric current in amperes, acceleration of gravity in meters per second squared).

b) Relative are called measurements of the ratio of a quantity to a quantity of the same name, playing the role of a unit, or measuring a quantity in relation to a quantity of the same name, taken as the initial one (measurement of the relative humidity of air, defined as the ratio of the amount of water vapor in 1 m "3 of air to the amount of water vapor that saturates 1 mj of air at a given temperature).

5) By the nature of the change in the measured value of the measurement:

a) Static- used to measure random processes, and then to determine the average value;

b) Constants- used to control continuous processes.

6) By the amount of measurement information measurements:

a) Single measurements- this is one measurement of one quantity, i.e. the number of measurements is equal to the number of measured values. The practical application of this type of measurement is always associated with large errors.

b) Multiple measurements- characterized by an excess of the number of measurements of the number of measured values. The advantage of multiple measurements is a significant reduction in the influence of random factors on the measurement error.

The main characteristics of measurements are:

Measurement principle;

Measurement method;

Error;

Accuracy;

Right;

Credibility.

Measuring principle- a physical phenomenon or a set of physical phenomena underlying measurements (measurement of body weight by weighing using gravity proportional to the mass, temperature measurement using the thermoelectric effect).

Measurement method- a set of techniques for using principles and measuring instruments. Measuring instruments are used technical means with standardized metrological properties.

Distinguish direct assessment methods and comparison methods.

When measuring direct assessment the desired value of the quantity is determined directly by the reading device of the measuring instrument, which is graduated in the appropriate units.

Comparison method with measure - a measurement method in which a measured value is compared with a reproducible measure (for example, comparison of mass on a beam balance). Distinctive feature comparison methods is the direct participation of the measure in the measurement procedure, while in the method of direct assessment, the measure is not explicitly present during measurement, and its dimensions are transferred to the reading device (scale) of the measuring instrument in advance, when it is calibrated. The comparing device is mandatory in the comparison method.

The measure comparison method has several flavors: the null method, the differential method, the override method, and the coincidence method.

Zero method(or full equilibration method) - a comparison method with a measure, in which the net effect of the influence of the measured quantity and the counter effect of the measure on the comparator is reduced to zero.

For example... Measurement of mass on an equal-arm balance, when the effect on the balance of the mass m x is completely balanced by the mass of the weights m 0 (Figure 2).

Figure 2 - Full equilibration method

At differential method complete equilibration is not performed, and the difference between the measured value and the value reproduced by the measure is counted on the scale of the device.

For example. Measurement of mass on an equal-arm balance, when the effect of the mass mx on the balance is partially balanced by the mass of the weights m 0 , and the difference in masses is counted on a scale of scales, graded in units of mass (Figure 3).

Figure 3 - Differential method

In this case, the value of the measured quantity m х = m 0 + m, where m — balance readings

Substitution method - a method of comparison with a measure in which the measured quantity is replaced by a known quantity reproducible by the measure.

For example: Weighing on a spring scale. The measurement is made in two steps. First, the weight to be weighed is placed on the scale pan and the position of the balance indicator is noted; then the mass m x is replaced by the mass of weights m 0, selecting it so that the balance indicator is set exactly in the same position as in the first case. It is clear that m х = m 0, (Figure 4).

Figure 4 - Substitution method

V method of coincidence the difference between the measured value and the value of the reproduced measure is measured using the coincidence of the scale marks or periodic signals.

For example . Measuring the number of shaft revolutions with a stroboscope - the shaft is periodically illuminated by flashes of light, and the frequency of the flashes is selected so that the mark applied to the shaft appears motionless to the observer. The method of coincidence, which uses the coincidence of the main and vernier marks of the scales, is implemented in vernier instruments used to measure linear dimensions.

Measurement error- deviation of the measurement result from the true value of the measured value. The error is caused by the influence of many factors, such as: the nature of the measured value, the quality of the measuring instruments used, the measurement method, the measurement conditions (temperature, humidity, pressure, etc.), the individual characteristics of the person performing the measurements, etc. Under the influence of these factors the measurement result will differ from the true value of the measured value.

Accuracy of measurements- a qualitative characteristic of measurements, reflecting the proximity of their results to the true value of the measured value.

Quantitatively, the accuracy can be expressed by the value "accuracy class". This is a characteristic that depends on the way of expressing the limits of permissible errors of measuring instruments. The introduction of an accuracy class pursued the goal of classifying measuring instruments by accuracy. At present, when the schemes and designs of measuring instruments have become more complex, and the areas of application of measuring instruments have greatly expanded, other factors also began to significantly affect the measurement error: changes in external conditions and the nature of changes in the measured quantities over time.

The error of measuring devices has ceased to be the main component of the measurement error, and the accuracy class does not allow to fully solve the practical problems listed above. The area of ​​practical application of the characteristic "accuracy class" is limited only by such measuring instruments that are designed to measure static values. In international practice, the "accuracy class" is set only for a small part of the instruments.

Correctness of measurements- the quality of measurements, reflecting the closeness to zero of systematic errors in their results (i.e. such errors that remain constant or change regularly when repeated measurements of the same quantity). The correctness of measurements depends, in particular, on how much the actual size of the unit in which the measurement is made differs from its true size (by definition), i.e. on the extent to which the measuring instruments used for this type of measurement were correct (correct).

Credibility characterizes confidence in the measurement results and divides them into two categories: reliable and unreliable, depending on whether the probabilistic characteristics of their deviations from the true values ​​of the corresponding quantities are known or unknown. Therefore, such probabilities should be considered as criteria for the reliability of control in order to correctly characterize the quality and safety parameters within the tolerance limits.

The presence of an error limits the reliability of measurements, i.e. introduces a limitation in the number of reliable significant digits of the numerical value of the measured value and determines the accuracy of measurements. The characteristics of the measurement error should be selected during the control of product samples in accordance with the requirements of the reliability of control.

Measurements as the main object of metrology are mainly related to physical quantities:

Physical quantity- one of the properties of a physical object, phenomenon, process, which is qualitatively common for many physical objects, while differing in quantitative value.

A physical quantity, which, by definition, is assigned a numerical value equal to one, is called unit of physical quantity.

Distinguish between basic and derived units.

Basic units of physical quantities are selected arbitrarily, regardless of other units (unit of length - meter, unit of mass - kilogram, unit of temperature - degree, etc.)

Units formed using formulas expressing the relationship between physical quantities are called derived units. In this case, the units of quantities will be expressed in terms of units of other quantities. For example, the unit of speed is a meter per second (m / s), and the unit of density is kilogram per meter squared (kg / m 2).

Different units of the same size differ from each other in their size. Such units are called multiples(for example, kilometer - 10 3 m, kilowatt - 10 3 W) or practical (for example, millimeter - 10 -3 m, millisecond - 10-3 s). Such units are obtained by multiplying or dividing an independent or derived unit by an integer, usually 10.

Units of physical quantities are combined according to a certain principle into systems of units. These principles are as follows: arbitrarily set units for certain quantities, called basic units and according to the formulas, all derived units for a given area of ​​measurements are obtained through the basic ones. The set of basic and derived units belonging to a certain system of quantities and formed in accordance with the accepted principles is system of units of physical grandeur.

The variety of systems of units for different areas of measurement created difficulties in scientific and economic activities both in individual countries and on an international scale. Therefore, it became necessary to create a unified system of units that would include units of quantities for all branches of physics.

The international system of units consists of seven basic units, two additional units and the required number of derived units.

The main ones are:

The unit of length is a meter - the length of the path that light travels in a vacuum in 1/299792458 fraction of a second;

Unit of mass - kilogram - mass equal to the mass of the international prototype of the kilogram;

The unit of time is a second - the duration of 9192631770 periods of radiation corresponding to the transition between two levels of the hyperfine structure of the ground state of the cesium-133 atom in the absence of disturbance from external fields;

The unit of electric current - ampere - is the strength of a constant current, which, when passing through two parallel conductors of infinite length and negligible circular cross-section, located at a distance of 1 m from one another in a vacuum, would create a force equal to 2 between these conductors. 10 ~ 7 N for each meter of length;

The unit of thermodynamic temperature, the kelvin, is a fraction of the thermodynamic temperature of the triple point of water. The use of the Celsius scale is also allowed;

The unit of the amount of matter is the mole - the amount of matter in a system containing the same number of structural elements as atoms are contained in a carbon-12 nuclide weighing 0.012 kg;

The unit of luminous intensity - candela - luminous intensity in a given direction of a source emitting monochromatic radiation with a frequency of 540-10 12 Hz, the energy intensity of which in this direction is 1/683 W / sr ".

The first three units (meter, kilogram, second) make it possible to form derived units for measuring mechanical and acoustic quantities. When added to the indicated fourth unit - kelvin, it is possible to form derived units for measuring thermal quantities.

Units (meter, kilogram, second, ampere) serve as the basis for the formation of derived units in the field of electrical, magnetic measurements and measurements of ionizing radiation. The unit mol is used to form units in the field of physical and chemical measurements.

Additional units are:

Flat angle unit- radian and solid angle unit- steradians are used to form derived units associated with angular quantities (for example, angular velocity, luminous flux, etc.).

MEASUREMENT SCALES

Scale of names is a qualitative, not a quantitative scale, it does not contain zero and units of measurement (for example, a color scale).

Such scales are used to classify objects, the properties of which are manifested only in relation to equivalence (coincidence or non-coincidence). These properties cannot be considered physical quantities; therefore, scales of this type are not PV scales. In the naming scales, assessment is carried out using the human sense organs, the most adequate is the result chosen by the majority of experts. Since these scales are characterized only by equivalence relations, they lack the concepts of zero, "more or less" and units of measurement.

Order scale - characterizes the value of the measured value in points (for example, earthquake scale; wind force, etc.).

It is monotonically changing and allows you to establish the relationship "more - less" between the quantities that characterize this property. Zero exists or does not exist, but it is fundamentally impossible to introduce units of measurement, since the proportionality relation has not been established for them and, accordingly, it is impossible to judge how many times more or less specific manifestations of a property are.

Interval scale- has a conditional zero value, and the intervals are set by agreement (eg, time scale, length scale).

These scales are further development order scales. The scale consists of equal intervals, has a unit of measurement and an arbitrary starting point - zero point. These scales include chronology, temperature scales.

The scale of the ratio has a natural zero value, and the unit of measurement is set by agreement, depending on the requirements for the accuracy of measurement (for example, a weight scale).

From a formal point of view, this scale is a scale of intervals with a natural origin. All values ​​are applicable to the values ​​obtained on the scale of relations. arithmetic operations, which is of great importance when measuring PV.