Flow meters can be classified into two major categories based on the measured objects: closed pipes and open channels. According to the measurement purpose, it is divided into total quantity measurement and flow measurement, and the corresponding instruments are respectively called total quantity meters and flow meters. By choosing the appropriate flow meter, the flow rate of the fluid can be accurately measured, which helps to improve work efficiency and reduce production costs. Therefore, flow meters play an important role in industrial production.
A flowmeter is an instrument widely used in industrial production and scientific research fields to measure the flow rate of fluids in pipelines. According to the most popular and widely used classification methods at present, they mainly include volumetric flowmeters, differential pressure flowmeters, float flowmeters, turbine flowmeters, electromagnetic flowmeters, vortex flowmeters in fluid oscillation flowmeters, mass flowmeters, insertion flowmeters and probe flowmeters.
1. Volumetric flowmeter: A volumetric flowmeter determines the flow rate by measuring the volume of the fluid passing through the instrument. Its principle is simple and it has good stability. It is suitable for occasions where the requirements for flow rate changes are not high, such as general liquid conveying systems;
2. Differential pressure flowmeter: The differential pressure flowmeter calculates the flow rate by measuring the pressure difference of the fluid in the pipeline. It features a simple structure and high reliability, and is widely used in the flow measurement of liquids, gases and steam;
3. Float flowmeter: The float flowmeter makes the float float up and down in the pipeline by the buoyancy of the fluid, and the flow rate is determined according to the position of the float. It is suitable for occasions with small flow rates and low requirements for measurement accuracy;
4. Turbine flowmeter: The turbine flowmeter works by the fluid driving the turbine to rotate and calculates the flow rate based on the rotational speed. It features high precision and fast response, and is widely used in industries such as petroleum, chemical engineering, and water conservancy;
5. Electromagnetic flowmeter: The electromagnetic flowmeter measures the flow of conductive fluids by using Ampere's law, without the need to measure parameters such as the density and viscosity of conductive liquids. It is suitable for the flow measurement of various liquids;
6. Mass flowmeter: The mass flowmeter directly measures the mass of the fluid passing through the pipeline within a unit of time, is not affected by fluid density, temperature, etc., and features high accuracy and good stability;
7. Insertable flowmeter: The insertable flowmeter measures fluid flow by inserting the sensor into the pipe interior and is suitable for applications with large pipe diameters and high flow rates;
8. Probe-type flowmeter: The probe-type flowmeter measures velocity by inserting a probe into the fluid. It has a simple structure and is easy to use. It is suitable for measuring liquids with low flow rates and low viscosity.
All kinds of flowmeters are widely used in different fields. Among them, turbine flowmeters, electromagnetic flowmeters and differential pressure flowmeters occupy a large share in domestic and foreign markets. New flowmeter technologies such as mass flowmeters and insertable flowmeters are also constantly developing. With the development of industrial automation, the requirements for the accuracy, reliability and multi-functionality of flowmeters are constantly increasing. In the future, flowmeter technology will continue to develop towards high performance and intelligence.
