We are a technology company. Our main products are Energy Meter Test Bench, etc. Let me introduce you to the origin of electromagnetic phenomena!

　　Research the technical science of electrical quantities, magnetic quantities and various non-electrical quantities that can be converted into electrical quantities.

　　Electromagnetic phenomena are one of the most common physical phenomena in nature. Before people have revealed the relationship between electricity and magnetism, they can only make simple instruments based on their own force effects to observe the phenomena of electricity and magnetism respectively. The appearance of magnetic measuring instruments long preceded electrical measuring instruments. The earliest magnetic measuring instrument was Sinan in China (see History of Electrical Technology), which was actually a magnetic compass. The earliest record of magnetic measuring instruments in the West appeared at the end of the 16th century. W. Gilber introduced a magnetometry instrument called Versorium in his monograph "On Magnetism, Magnets, and the Giant Geomagnet". This instrument supports an arrow-shaped iron needle on the tip to observe the magnetic attraction phenomenon. Versorium was also the earliest electrical measuring instrument, and Gilber found that no matter what kind of metal was used to make the arrow-shaped needle, when the instrument approached a statically charged object, the metal needle would be attracted and deflected. In 1745, Г.B. Richman invented the first electrical measuring instrument with quantitative properties called the electrometer for the study of atmospheric electrical phenomena. The linen thread is 6cm long and weighs only 0.05g. When the metal rod moves close to the charged body or connects with the charged body, the flax thread is repulsed and spreads out an angle along the 1/4 arc-shaped plank. According to this, the strength of electric "power" can be distinguished. Later, some electrostatic measuring instruments of different structures appeared one after another.

　　In 1820, H.C. Oster discovered the magnetic effect of current; in 1821, A.-M. Ampere clarified the effect of attracting or repulsive force between two current conductors; in 1831, M. Faraday discovered the phenomenon of electromagnetic induction. These discoveries have enabled scientists to master electrokinetic, magnetic and mechanical forces, as well as the relationship between dynamic magnetism and electricity, leading to a leap in the measurement of electricity and magnetism and the development of related instruments, and the emergence of mechanical Various mechanical indicating electric meters and recording instruments that use torque, and are indicated by pointers or light points, as well as those that compare unknown quantities to be measured with standard quantities in specially designed circuits (such as electric bridges, potentiometers, etc.). A comparative measuring instrument (referred to as a comparative instrument).

　　Electromagnetic measurement objects and measurement process Electromagnetic measurement objects are mainly electrical and magnetic. Electrical quantities include electrical quantities (such as voltage U, current I, electrical power P, reactive power Q, power factor, etc.) and electrical parameters (such as resistance R, capacitance C, self-inductance L, mutual inductance M, etc.). Among them, U and I are basic quantities, and some other electrical quantities can be obtained indirectly through them. Magnetic quantities include magnetic flux Φ, magnetic flux density (magnetic induction intensity) B, magnetic field intensity H, magnetic permeability μ, iron loss, etc. Among them, B and H are the basic quantities. The digital measurement technology that appeared after the 1950s takes time, frequency (or pulse number) as the basic quantity.

　　Electromagnetic Measuring Instruments is also one of our products, welcome to visit our website!