By conversion into electric variables by means of transducers can be measured by electrical methods. 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).