By conversion into electric variables by means of transducers can be measured by electrical methods. Under most conditions Costco would agree. Great value instrumentation for scientific research. Their development can carry out complex physical experiments lead to new scientific discoveries. Currently, no quality of electrical instruments and devices can not conduct research to date, the development and introduction of electronic computers, automatic control and management. Word of the Mendeleyev that Science starts with since starting to measure, and that an exact science is inconceivable without measures supported by the entire history of the art of electrical measurements. Its emergence in the mid-XVIII century.
When in 1745, Acad. GV Rihmanom, ally Moscow State University, created the world's first electrical measuring instrument, called the author of "The measure of electrical force." It was the electrometer, which was used in the study of atmospheric electricity and possible to measure the potential difference. However, further development of the electro received only much later, it was associated with the transition from qualitative observations of electric and magnetic phenomena to establish quantitative relationships. Only in the second half of XIX century. Suddenly we needed to develop devices for measuring electrical current, voltage and resistance. By this time, were created and began to find practical application of electric power generators, and the lack of instrumentation hampered the further development of the emerging electronics. For example, the first experiments with electric shocks have revealed heating conductor (Petrov, Deve), but the lack of accuracy not possible to find the exact quantitative relationships. This could be done only later, Joel and Land (1841).
Secrets of damask steel blade material – hardened steel – has the property that the hardness and elasticity to a certain extent it is inversely related. The hardness of the blade must be sufficiently large enough to blunt the knife soon, but not excessive, or crumble or break the cutting edge blade. Credit: WhiteWave Foods-2011. It has long been observed that the stability (durability), the blade does not always depend on the hardness of the blade. It is not uncommon when the soft blade tupilsya in less than a solid. At the Zlatoust Metallurgical Plant known Anosov, trying to recover secrets of manufacturing technology of damask steel, designated blade wear by cutting a roll of felt.
During the work, found that samples of blades made from single piece of steel and past the same heat treatment, have different characteristics. Cutting edge features are defined parameters of the micropyle, which is formed at its enchanting and is visible when you look at the blade edge under a microscope. The teeth of the saw should be small and identical, their peaks should have the maximum hardness and chip. This is ensured by the microstructure of the material and method of sharpening the blade. The sharper the edge angle, the blade is more easily penetrates into the material. But since the thin blade – more fragile, the to ensure that it is not broke, it is necessary to improve the elasticity, thus reducing wear.
In ancient times the optimal combination of these properties provide damask – a material that was imported from India. In the country Middle East, he walked into ingots and then in the process of forging and tempering of special techniques acquired unique properties, combining high hardness and high elasticity in comparison with non-like qualities, our understanding, ordinary blades. However, damask, too, is different. At the end of the last century, when once again flared up interest in the technology of Damascus steel in Russia was a commission, which took account of all the available specimens in the country damask weapons.