Types and principles of flowmeters
Turbine flowmeterTurbine flowmeter is the main type of speed flow meter. It uses multi blade rotor (turbine) to sense the average flow velocity of fluid, so as to deduce the instrument of flow or total quantity. Generally, it is composed of two parts: sensor and display device. It can also be made into integral type.Turbine flowmeter and volumetric flowmeter, Coriolis mass flowmeter is called products in three categories of repeatability, precision in the best, as one of the ten types of flow meter, its product has been developed for the scale of many varieties and series of batch production.Advantage：(1) high accuracy, which is the most accurate flowmeter in all flowmeters;(2) good repeatability;(3) yuan zero drift, good anti-interference ability;(4) wide range;(5) compact structure.Shortcoming:(1) the calibration characteristics can not be maintained for a long time;(2) the property of fluid has a great influence on the flow characteristics.
Float flowmeterThe float flowmeter, also known as the rotor flowmeter, is a variable area flowmeter. The vertical cone enlarged upward in a pipe under the circular cross section, the float is powered by a liquid under gravity, which can float freely up and down in the cone tube.The float flowmeter is the most widely used flowmeter after the differential pressure flowmeter. It plays an important role in small and micro flow.
Displacement flowmeterVolumetric flowmeter, also known as constant displacement flowmeter, or PD flowmeter, is the most accurate type in flow meters. It uses a mechanical measuring element to continuously divide the fluid into a single known volume part. The volume of the fluid is measured according to the number of times the chamber repeats and fills the volume of the fluid.Volumetric flowmeter measuring element according to its classification, can be divided into elliptical gear flowmeter, scraper flowmeter, dual rotor flowmeter, rotary piston flowmeter, reciprocating piston flowmeter, disc flowmeter, liquid SELAED drum flowmeter, wet gas meter and membrane type gas meter etc..Advantage：(1) the measuring accuracy is high;(2) the condition of piping installation has no influence on the measuring accuracy;(3) it can be used for measuring high viscosity liquid;(4) wide range;(5) direct reading instrument, without external energy sources, can directly obtain the total amount, clear and easy to operate.Shortcoming:(1) the result is complicated and the volume is huge;(2) the type, caliber, medium and working condition of the tested medium are relatively large:(3) it is not suitable for high or low temperature occasions;(4) most instruments are only suitable for clean single-phase fluids;(5) noise and vibration.
