Where is the international standard of kilograms stored?

Accuracy is not superfluous. That is why the system of international measurements has been created and exists all over the world, expressed in the standards of all known measurements. And only the standard kilogram is allocated in the line of units of measurement. After all, he is the only one who has a physical real prototype. How much does it weigh and in what country is the international standard of kilograms stored, we will answer in this article.

What are the standards for?

Kilograms, such as oranges, weigh the same in Africa and in Russia? The answer is yes, almost. And all thanks to the international standard definition system Kilogram, meter, second and other physical parameters. Measure standards are necessary for mankind to ensure economic activity (trade) and construction (unity of drawings), industrial (unity of alloys) and cultural (unity of time intervals) and many other areas of activity. And if in the near future your iPhone breaks down, then it is very likely that this happened because of changes in the weight of the most important standard of mass.

History of standards

Each civilization had its own standards and standards, which succeeded each other after the lapse of centuries. In Ancient Egypt the mass of objects was measured in canthars or kikkars. In ancient Greece, these were talents and drachmas. And in Russia the mass of goods was measured in poods or spools. At the same time, people of different economic and political systems agreed that the unit of measurement of mass, length or other parameter would be comparable to a single contractual unit. Interestingly, even a pood in ancient times could differ by one third from merchants from different countries.

Physics and standards

Arrangements, often oral and conditional, worked until the person was seriously engaged in science and engineering. With the understanding of the laws of physics and chemistry, the development of industry, the creation of a steam boiler and the development of international trade, there was a need for more precise unified standards. Preparatory work was lengthy and painstaking. Physicists, mathematicians, chemists all over the world worked to find a universal standard. And in the first place - the international standard kilogram, because it is from the weight measure push other physical parameters (Ampere, Volt, Watt).

The Metric Convention

A significant event occurred in the suburbs of Paris in 1875. Then for the first time 17 countries (and Russia among them) signed a metric convention. This is an international treaty that ensures the unity of standards. Today, 55 countries have joined it as full members and 41 countries as associate members. At the same time, the International Bureau of Weights and Measures and the International Committee for Weights and Measures were created, whose main task is to monitor the unity of standardization around the world.

Standards of the first metric convention

The meter of the meter was a ruler made of the alloy of platinum and iridium (9 to 1) in length to one forty millionth part of the Parisian meridian. The standard of a kilogram of the same alloy corresponded to a mass of one liter (decimeter cubic) of water at a temperature of 4 degrees Celsius (the highest density) at a standard pressure above sea level. The standard of the second was 1/86400 part of the duration of the average solar day. All 17 countries of the convention participants received a copy of the standard.

Place Z

Prototypes and the original of the standard are now stored in the Chamber of Weights and Measures in the city of Sevres near Paris. It is in the suburbs of Paris that the place where the standard is stored Kilogram, meter, candela (luminous intensity), ampere (amperage), kelvin (temperature) and mole (as a unit of substance, there is no physical standard). The system of measures and weights, which is based on these six standards, is called the International System of Units (SI). But the history of standards did not end there, it was only just beginning.

SI

The system of standards that we use - SI (SI), from the French Systeme International d'Unites - includes seven basic values. This meter (length), kilogram (mass), ampere (amperage), candela (luminous intensity), kelvin (temperature), mole (amount of substance). All other physical quantities are obtained by various mathematical calculi using base values. For example, a unit of force is equal to kg x m / s ² . All countries of the world, except the United States, Nigeria and Myanmar, use the SI system for measurements, which means comparing the unknown quantity with the standard. A standard is the equivalent of physical meaning, about which all agreed that it is absolutely accurate.

The standard kilo is how much?

It would seem that it is easier - the standard of 1 kilogram is the weight of 1 liter of water. But in fact, this is not entirely true. What to take as a standard kilogram of about 80 prototypes - the question is quite complicated. But by chance, the optimal alloy was selected, which lasted more than 100 years. The standard of kilogram mass is made of a platinum (90%) alloy and iridium (10%), and is a cylinder whose diameter is equal to the height and is 39.17 mm. There were also made his exact copies, with a quantity of 80 pieces. Copies of the standard kilogram Are in the countries-participants of the convention. The main standard is stored in the suburbs of Paris and covered with three sealed capsules. Wherever there is a standard kilogram, With a periodicity of ten years reconciliation is conducted with the most important international standard.

The most important standard

The international standard of the kilogram was cast in 1889 and stored in Sevres in France in the safe of the International Bureau of Weights and Measures, covered with three hermetic glass caps. Only three high-ranking representatives of the bureau have the keys to this safe. Together with the main standard in the safe there are six of his doubles or successors. Every year the main measure of weight, which is taken as the standard kilogram, is solemnly extracted for examination. And every year it is getting thinner and thinner. The reason for this loss of weight is the detachment of atoms when the sample is extracted.

Russian version

A copy of the standard is also in Russia. He is stored in the All-Russian Research Institute of Metrology. Mendeleev in St. Petersburg. These are two platinum-iridium prototypes - No. 12 and No. 26. They are on a quartz stand, covered with two glass caps and closed in a metal safe. The air temperature inside the capsules is 20 ° C, and the humidity is 65%. Domestic prototype has a weight of 1, 000000087 kilograms.

The standard of a kilogram grows thin

Verification of the standard showed that the accuracy of national standards is about 2 μg. All of them are stored under similar conditions, and calculations show that the standard kilogram for a hundred years loses weight 3 x 10 ^-8 weight. But by definition, the mass of the international standard corresponds to 1 kilogram, and any changes in the real mass of the standard lead to a change in the value of the kilogram itself. In 2007, it became clear that the kilogram cylinder began to weigh 50 microgram less. And the reduction in its weight continues.

New technologies and a new standard of weight measures

To eliminate errors, a new structure of the standard kilogram is being searched. There are developments by definition of a standard of a certain number of isotopes of silicon-28. There is a project called "Electronic kilogram". The National Institute of Standards and Technology (2005, USA) designed a device based on measuring the power needed to create an electromagnetic field capable of lifting 1 kg of mass. The accuracy of this measurement is 99.999995%. There are developments in determining the mass with respect to the rest mass of the neutron. All these developments and technologies will make it possible to avoid binding to the physical mass standard, to achieve higher accuracy and the possibility of reconciliation anywhere in the world.

Other promising projects

And while the world's luminaries of science are determined which way to solve the problem is more reliable, the most promising project is considered, in which the mass will not change with the passage of time. Such a standard would be a cubic-shaped body of carbon-12 isotope atoms with a height of 8.11 centimeters. In such a cube there will be 2250 x 281489633 carbon-12 atoms. Researchers from the National Institute of Standards and Technology in the US propose to define the standard kilogram, using the Planck constant and the formula E = mc ^ 2.

Modern metric system

Modern standards are not the same as they were before. The meter, initially correlated with the circumference of the planet, today corresponds to the distance that a beam of light passes in one 299792458 second. But the second - this is the time for which passes 9192631770 vibrations of the cesium atom. The advantages of quantum accuracy in this case are obvious, because they can be reproduced anywhere in the world. As a result, the only standard that exists physically remains as long as the standard of the kilogram.

How much is the standard?

Having existed for more than 100 years, the standard already costs a lot, as a unique and artifact object. In general, to determine the price equivalent, it is necessary to calculate the number of atoms in a kilogram of pure gold. The number is obtained from the order of 25 digits and this is without taking into account the ideological value of this artifact. But while the sale of the standard kilogram early, because the world community has not yet got rid of the only remaining physical standard of the international system of units.

Interesting about measurements

In all time zones of the planet, time is determined with respect to the universal time of UTC (for example, UTC + 4: 00). It is noteworthy that the abbreviation has no decoding at all, it was adopted in 1970 by the International Telecommunication Union. Two options were proposed: English CUT (Coordinated Universal Time) and French TUC (Temps Universel Coordonné). Have chosen the average neutral abbreviation.

At sea, the "node" measurement is used. To measure the speed of the ship used a special log with nodes at the same distance, which was thrown overboard and counted the number of nodes for a certain period of time. Modern instruments are much more perfect than a rope with nodes, but the name remains.

The word scrupulousness, whose importance is extreme accuracy and accuracy, has come to the tongues from the name of the ancient Greek standard of weight - scrupula. It was 1.14 grams and was used for weighing silver coins.

The name of monetary units also often originates in the names of weight measures. So, sterling in Britain were called silver coins, and 240 such coins weighed a pound. In ancient Russia in the course were "hryvnia silver" or "hryvnia gold", which meant a certain number of coins, expressed in weight equivalent.

A strange measurement of the power of cars in horsepower has a very real origin. The inventor of the steam engine, James White, was just so determined to demonstrate the advantage of his invention over traction vehicles. He calculated how much the horse can lift the load per minute and designated this quantity as one horsepower.