Metric system of measures: table, units and standards. The Metric Measure System and the International System of Units

The international system of units is a structure based on the use of weight indicators in kilograms and length in meters. Since its inception, there have been various versions of it. The difference between them was the choice of key indicators. Today, many countries use units of measure in the SI system. In it, the elements are the same for all states (with the exception of the United States, Liberia, Burma). This system is widely used in various areas - from everyday life to scientific research.

Features

A metric system of measures is an ordered set of parameters. This significantly distinguishes it from the previously used traditional methods of determining those or other units. To denote any value, the metric system of measures uses only one basic indicator, the value of which can vary in multiple fractions (achieved by the use of decimal add-on elements). The main advantage with this approach is the simpler use. This eliminates a huge number of different unnecessary units (feet, miles, inches and others).

Time parameters

For a long period, a number of scientists have tried to present time in metric units. It was suggested to divide the day into smaller elements - milliseconds, and the corners - to 400 grads or to take a complete cycle of turnover for 1000 milliovorotov. Over time, due to inconvenience in use, I had to refuse this idea. Today, time in the SI is denoted by seconds (composed of milliseconds) and radians.

History of occurrence

It is believed that the modern metric system of measures was born in France. In the period from 1791 to 1795, a number of important legislative acts were adopted in this country. They were aimed at determining the status of the meter - one ten-millionth part of the 1/4 meridian from the equator to the North Pole. July 4, 1837 adopted a special document. According to him, the mandatory use of the elements, of which the metric system of measures was composed, was officially approved in all economic transactions carried out on the territory of France. In the future, the adopted structure began to spread to the neighboring countries of Europe. In view of its simplicity and convenience, the metric system of measures gradually replaced most of the national ones used before. It can also be used in the US and UK.

Basic values

For the unit of measurement, the founders of the system, as noted above, took a meter. The element of mass was gram - the weight of one million m ^{3 of} water at its standard density. For more convenient application of units of a new system, the creators have come up with a way to make them more accessible - by making standards from metal. These models are made with an ideal accuracy of reproduction values. Where are the standards of the metric system, will be discussed below. Later, when using these models, people realized that comparing the desired value with them is much easier and more convenient than, for example, with a quarter of the meridian. At the same time, when determining the mass of the desired body, it became obvious that it is much more convenient to evaluate it by reference than with the corresponding amount of water.

"Archival" samples

By decision of the International Commission in 1872, a specially manufactured meter was adopted as the standard for measuring the length. At the same time, the members of the commission decided to take a special kilogram as the standard for measuring mass. It was made of alloys of platinum and iridium. The "archival" meter and kilogram are in permanent storage in Paris. In 1885, on the 20th of May, a special Convention was signed by representatives of seventeen countries. Within its framework, the procedure for determining and using measurement standards in scientific research and work was regulated. This required special organizations. These include, in particular, the International Bureau of Weights and Measures. Within the framework of the newly created organization, the development of mass and length samples began, with the subsequent transfer of their copies to all participating countries.

Metric system of measures in Russia

More and more countries used the adopted samples. Under the circumstances, Russia could not ignore the emergence of a new system. Therefore, the Law of July 4, 1899 (author and developer - D. I. Mendeleev), it was authorized for use in an optional manner. It became compulsory only after the adoption by the Provisional Government of the corresponding decree of 1917. Later, its application was fixed by the decision of the Council of People's Commissars of the USSR of July 21, 1925. In the twentieth century, most countries switched to measurements in the international system of SI units. The final version of it was developed and approved by the XI General Conference in 1960.

Post-Soviet time

The collapse of the USSR coincided with the moment of rapid development of computer and home appliances, the main production of which is concentrated in the countries of Asia. Large quantities of goods of these producers began to be imported into the territory of the Russian Federation. At the same time, Asian states did not think about possible problems and inconvenience of exploitation of their goods by the Russian-speaking population and supplied their products with a universal (in their opinion) instruction in English, using American parameters. In everyday life, the designation of quantities in the metric system was replaced by elements used in the United States. For example, the sizes of computer disks, diagonal monitors and other components are indicated in inches. At the same time, initially the parameters of these components were indicated strictly in the values of the metric system (the width of the CD and DVD, for example, is equal to 120 mm).

International use

At present, the most common on the planet Earth is the metric system of measures. The table of masses, lengths, distances and other parameters makes it easy to translate certain indicators into others. Countries, for certain reasons have not switched to this system, every year there are fewer and fewer. Such states, which continue to use their own parameters, include the United States, Burma and Liberia. America uses in the branches of scientific production the SI system. American parameters were used in all others. The United Kingdom and Saint Lucia have not yet switched to the world SI system. But, it must be said that the process is in an active stage. The last of the countries that finally switched to the metric system in 2005 was Ireland. Antigua and Guyana only produce a transition, but the pace is very slow. The situation in China is interesting, which officially passed to the metric system, but the use of ancient Chinese units continues on its territory.

Aviation parameters

The metric system of measures is recognized almost universally. But there are certain industries in which it has not taken root. Aviation still uses a measurement system based on quantities such as foot and mile. The application of this system in this area has developed historically. The position of the International Civil Aviation Organization is unambiguous - a transition to metric values must be made. However, only a few countries adhere to these recommendations in their pure form. Among them are Russia, China and Sweden. Moreover, the civil aviation structure of the Russian Federation, in order to avoid confusion with international control centers, in 2011 partially adopted a system of measures, the basic unit of which is foot.