1832 Faraday on both sides of the River Thames Waterloo Bridge, chose to the direction of the direction of the vertical magnetic field of the flow, put down two metal rods as electrodes to measure the flow rate of the river. This is the world's first electromagnetic flowmeter test. However, due to the electrochemical reaction, thermoelectric effect and other reasons, the signal is false, and the flow velocity signal is shorted. The condition of the measurement was limited, so he failed. Fortunately, he saw the success of Woli Maggot Lon in 1851 to measure the tidal test of the English Channel by using electromagnetic induction.
1917, Smith and Spirehain obtained the application of electromagnetic induction to the principle of manufacturing ship velocimetry patents, and recommended the use of AC excitation to overcome the impact of water polarization, so as to open up the application of electromagnetic velocity meter in oceanography.
1930, Williams placed copper sulfate solution in a non-conductive circular tube in a DC magnetic field, detecting the DC voltage between the two electrodes in a circular tube is proportional to the flow rate, which becomes a simple electromagnetic flowmeter. For the first time, Williams analyzed the influence of velocity distribution on the measurement in the circular tube with mathematical method, and proposed the theory of the measuring accuracy of the electromagnetic flowmeter without affecting the axial velocity distribution of the center of pipe. Although his analysis is mathematically wrong, it has the basic theory of electromagnetic flowmeter.
Before and after 1932, according to Fabm's suggestion, biologists Willama, a, and the use of electromagnetic flowmeter to measure and record instantaneous arterial blood flow has been successful
Before and after 1932, according to Fabre's suggestion, biologists Willama, a, the use of electromagnetic flowmeter to measure and record instantaneous arterial blood flow has been successful. After the Second World War, the atomic energy industry has developed rapidly, so it can measure the permanent magnet of liquid metals, so that the electromagnetic flowmeter is developed and applied. However, since the electronic technology is still lagging behind, its use of the field can not be extended to the general industry.
1950, the Dutch first used electromagnetic flowmeter on the dredger to measure mud flow. The electromagnetic flowmeter was used in general industrial production in the United States.
1955, Japan's North exhibition motor and Yokogawa Motors respectively introduced the United States Fisher&Prter Company and Foxbom Company's electromagnetic flowmeter products, after continuous digestion, and improved, its electromagnetic flowmeter quickly entered the world's advanced ranks.
Before and after 1955, the former Soviet Union, Britain, Germany also succeeded in producing electromagnetic flowmeter.