The working principle of electromagnetic flowmeter

The basic concept of the electromagnetic flowmeter is Faraday's basic law of electromagnetic induction, that is, when the electric conductor in the electromagnetic field laser cutting magnetic field fitness movement, the two sides of the induced electromotive force E is: where, K is the instrument panel constant;B is the magnetic induction compressive strength (T);V is the average fitness speed of the electric conductor m/s;D is the nominal diameter (m) of the pipeline.

The working principle of electromagnetic flowmeter

Principle of electromagnetic flowmeter

The principle and structure of electromagnetic flowmeter consist of flow controller and converter.

When measuring the flow rate, the conductivity of the liquid is equal to the conducting metal rod in the Faraday experiment, passing through the electromagnetic field at an average rate of v perpendicular to the direction of the flow.The fluidity of a conductive liquid, induced at the measured level by a voltage proportional to the mean water flow.Its induced voltage data signal E is detected by a pair or a pair of left and right electrical levels immediately touching the liquid.

According to the volume flow formula of fluid mechanics

According to the formula (2), Q and v are proportional to the number of culvert one-to-one correspondence, so E and Q are proportional to the number of culvert one-to-one correspondence, and the induced voltage E is measured, that is, the volume flow Q of the substance is measured.

The measured induced voltage E is sent by the cable to the converter, which is solved according to the intelligent system, and then the LCD display information, or converted into the standard data signal 4-20ma output.

Electromagnetic flowmeter characteristics

(1) there are no frictional resistance components in the measuring pipeline, no additional working pressure damage, and it is not easy to produce obstruction, which has obvious practical significance of environmental protection and energy saving;

(2) the component cannot be moved in the measuring pipeline, which is not easy to be damaged, so the controller has a long life;

(3) the connection segment required by the controller is short and convenient to install;

(4) effective selection of electrical grade and lining raw materials, corrosion and wear resistance;

(5) dual measurement system software, which can measure positive and negative flow;

(6) the flow is measured as volume flow, which will not be harmed by the relative density, viscosity, temperature, working pressure and conductivity change of the flow;

(7) the data signal of the controller's induced voltage is linearly correlated with the mean water flow, with a high precision (±0.3 ~ -0.5%) and a wide measurement range (1:150).

Porcelain city Shanghai instruments co., LTD. Is China's first tiny elliptical gear manufacturers, by Mr Stone (Siemens) senior engineers involved research and development, with independent intellectual property rights, completely using Siemens CNC processing center production and processing equipment, to ensure the minimum flow rate of 0.1 ml/min, which is rare in the world, the precision is over 90%.