Metric system. History of the creation of the metric system of measures Examples of the metric system of measures

Metric system, decimal system of measures, collection of units physical quantities, which is based on the unit of length - meter. Initially, the Metric system of measures, in addition to the meter, included units: area - square meter, volume - cubic meter and mass - kilogram (mass of 1 dm 3 water at 4 ° C), as well as liter(for capacity), ar(for land area) and ton(1000 kg). An important distinctive feature of the Metric system of measures was the method of formation multiples of units And submultiple units , which are in decimal ratios; To form the names of derived units, prefixes were adopted: kilo, hecto, soundboard, deci, centi And Milli.

The metric system of measures was developed in France during the Great Age french revolution. At the suggestion of a commission of major French scientists (J. Borda, J. Condorcet, P. Laplace, G. Monge, etc.), the unit of length - the meter - was adopted as a ten-millionth part of 1/4 of the length of the Parisian geographical meridian. This decision was determined by the desire to base the Metric system of measures on an easily reproducible “natural” unit of length associated with some practically unchanging object of nature. The decree introducing the metric system of measures in France was adopted on April 7, 1795. In 1799, a platinum prototype of the meter was manufactured and approved. The dimensions, names and definitions of other units of the Metric system of measures were chosen so that it was not national in nature and could be adopted by all countries. The metric system of measures acquired a truly international character in 1875, when 17 countries, including Russia, signed metric convention to ensure international unity and improvement of the metric system. The metric system of measures was approved for use in Russia (optional) by the law of June 4, 1899, the draft of which was developed by D. I. Mendeleev, and introduced as mandatory by the decree of the Council of People's Commissars of the RSFSR of September 14, 1918, and for the USSR by decree Council of People's Commissars of the USSR dated July 21, 1925.

Based on the Metric system of measures, a whole series of particular measures arose, covering only certain sections of physics or branches of technology, systems of units and individual non-system units. The development of science and technology, as well as international relations led to the creation, based on the Metric system of measures, of a unified system of units covering all areas of measurement - International System of Units(SI), which has already been accepted as mandatory or preferred by many countries.

Despite the fact that the metric, decimal system of measures and weights has long been adopted in continental Europe, we are constantly faced with English and American units of measurement of length, area, volume and weight. The most common among them are inch, foot, yard, mile, acre, pound, pint, barrel.

Many, I am sure, have seen a mysterious inscription on bottles with various liquids fl. oz. In England and the USA there are many other, less well-known units of measurement.

Most often we use these units of measurement when talking about such common things as the size of a car tire or TV screen. The size is usually already indicated in inches right in the model name. The same is true with the diameter of metal and plastic pipes, the size of wrenches and the bolts and nuts themselves. The mileage of American cars is indicated in miles. When calling the price of oil, they say: “price per barrel,” and the weight of gold is often called in ounces. Some cookbooks also list weight in pounds and volume in ounces or quarts.

What does the inscription lb or lbs mean in American stores? Read about this at the bottom of the page.

And one more small note: don’t try to remember all this, that’s why reference books were invented, so as not to overload your memory with routine. So take a look!

All that remains is to wish you seven feet under the keel and go directly to the table!

Word pound comes from Latin libra pondo. First word libra means “scales” - actually a device for measuring weight and an astrological sign, since the constellation looks like scales. Second - pondo- just weight. Accordingly, the whole combination libra pondo means "pound of weight" (or, if you prefer, "pound of weight"). In modern English language"libra pondo" was modified and shortened to "pound", but the abbreviation remained from the Latin libra - lb.

Often in stores English speaking countries you can see the reduction lbs to denote pounds, which, strictly speaking, is an error, because. According to international convention, the pound is a unit of measurement, and there are no abbreviations for units of measurement in English plural, also, by the way, as in Russian. We don't write KGy or KWe.

International decimal system measurements based on the use of units such as the kilogram and meter is called metric. Various options metric system have been developed and used over the past two hundred years, and the differences between them consist mainly in the choice of basic, basic units. On this moment the so-called International system of units (SI). The elements that are used in it are identical throughout the world, although there are differences in individual details. International system of units is very widely and actively used all over the world, both in Everyday life, and in scientific research.

For now Metric system used in most countries of the world. There are, however, several large states that still use units based on such units as pound, foot and second - English system measures These include the UK, USA and Canada. However, these countries have also already adopted several legislative measures aimed at moving towards Metric system.

She herself was born in the middle XVIII century in France. It was then that scientists decided that they should create system of measures, the basis of which will be units taken from nature. The essence of this approach was that they constantly remain unchanged, and therefore the entire system as a whole will be stable.

Length measures

• 1 kilometer (km) = 1000 meters (m)
• 1 meter (m) = 10 decimeters (dm) = 100 centimeters (cm)
• 1 decimeter (dm) = 10 centimeters (cm)
• 1 centimeter (cm) = 10 millimeters (mm)

Area measures

• 1 sq. kilometer (km 2) = 1,000,000 sq. meters (m 2)
• 1 sq. meter (m2) = 100 sq. decimeters (dm 2) = 10,000 sq. centimeters (cm 2)
• 1 hectare (ha) = 100 aram (a) = 10,000 sq. meters (m 2)
• 1 ar (a) = 100 sq. meters (m 2)

Volume measures

• 1 cu. meter (m 3) = 1000 cubic meters decimeters (dm 3) = 1,000,000 cubic meters. centimeters (cm 3)
• 1 cu. decimeter (dm 3) = 1000 cubic meters. centimeters (cm 3)
• 1 liter (l) = 1 cu. decimeter (dm 3)
• 1 hectoliter (hl) = 100 liters (l)

Weights

• 1 ton (t) = 1000 kilograms (kg)
• 1 quintal (c) = 100 kilograms (kg)
• 1 kilogram (kg) = 1000 grams (g)
• 1 gram (g) = 1000 milligrams (mg)

Metric system

It should be noted that the metric system was not immediately recognized. As for Russia, in our country it was allowed to be used after it signed metric convention. At the same time this system of measures for a long time it was used in parallel with the national one, which was based on such units as the pound, fathom and bucket.

Some old Russian measures

Length measures

• 1 verst = 500 fathoms = 1500 arshins = 3500 feet = 1066.8 m
• 1 fathom = 3 arshins = 48 vershoks = 7 feet = 84 inches = 2.1336 m
• 1 arshin = 16 vershok = 71.12 cm
• 1 vershok = 4.450 cm
• 1 foot = 12 inches = 0.3048 m
• 1 inch = 2.540 cm
• 1 nautical mile = 1852.2 m

Weights

• 1 pood = 40 pounds = 16.380 kg
• 1 lb = 0.40951 kg

Main difference Metric system from those previously used is that it uses an ordered set of units of measurement. This means that any physical quantity is characterized by a certain main unit, and all submultiples and multiples are formed according to a single standard, namely, using decimal prefixes.

Introduction of this systems of measures eliminates the inconvenience that previously resulted from the abundance of different units of measurement that have rather complex rules for transformation between themselves. Those in metric system are very simple and boil down to the fact that the original value is multiplied or divided by a power of 10.

Rice. 148. Making a blocking capacitor, a – collected sheets of foil and paper; Below is a view of the relative position of the foil sheets; b – the ends of the foil sheets are bent outward;

With – a clip made of sheet brass for clamping the ends of the foil; d – finished capacitor

3. TABLES OF CONVERSION OF MEASURES FOR DIFFERENT SYSTEMS

As we said earlier, in our presentation we tried to adhere to the currently accepted metric system of measures. However, in those cases where the old Russian or English measures have not yet fallen out of use in the sale of certain types of materials, we provided data on these measures.

In case any of the readers still have to translate metric measures in Russian or, with a more complete establishment of the metric system in our country, the old measures placed in the text - in metric ones, we give the following tables, covering all the data found in the previous chapters.

Comparison of metric and Russian measures

A. Comparison of metric and Russian measures.

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When was the metric system introduced in Russia?

The metric, or decimal, system of measures is a set of units of physical quantities, which is based on the unit of length - the meter. This system was developed in France during the revolution of 1789–1794. At the proposal of a commission of leading French scientists, one ten-millionth of a quarter of the length of the Paris meridian was adopted as a unit of length - a meter. This decision was determined by the desire to base the metric system of measures on an easily reproducible “natural” unit of length associated with a practically unchanging object of nature. The decree introducing the metric system of measures in France was adopted on April 7, 1795. In 1799, a platinum prototype of the meter was made and approved. The dimensions, names and definitions of other units of the metric system of measures were chosen so that it was not national in nature and could be applied in all countries. The metric system of measures acquired a truly international character in 1875, when 17 countries, including Russia, signed the Metric Convention to ensure international unity and improve the metric system. The metric system of measures was approved for use in Russia (optional) by the law of June 4, 1899, the draft of which was developed by D. I. Mendeleev. It was introduced as mandatory by a decree of the Council of People's Commissars of the RSFSR dated September 14, 1918, and for the USSR by a decree of the Council of People's Commissars of the USSR dated July 21, 1925.