Hot:13042013-11-02 01:28:17 From: FTD Automation Instruments
Knowledge of Several Flowmeter
The flow measurement is one of the four important process parameters (the other is the temperature, pressure and level). Closed pipe flowmeter with its use of technical classification;
PD meter used to measure the liquid or gas volume flow rate, it will flow into measurement in the space is calculated, and the number of rotation. Impeller, the gear, piston or hole board to shunt fluid. PD meter accuracy is higher, is a measure of the viscous liquid is one of the several methods. But it also can produce unrecoverable pressure error, and should be equipped with moving parts.
When the fluid flows through turbine flow time, fluid make rotor rotation. The rotation of the rotor speed and fluid speed related. Through the rotor feel fluid mean flow velocity, deduced flow or amount. Turbine flowmeter can accurately measure the clean liquid and gas. Like PD flowmeter, turbine flowmeter also can produce unrecoverable pressure error, also need moving parts.
Has the conductivity of fluid in the flows through electromagnetic field, by measuring the voltage can get the speed of the fluid. Electromagnetic flowmeter no moving parts, not affected by the influence of the fluid. In the full package when measuring conductivity liquid accuracy very high. Electromagnetic flowmeter can be used to measure the flow velocity of the fluid slurry.
Vortex flowmeter is in fluid put a piece of non streamline swim vortex happens body, swam vortex the speed with the speed of the fluid into a certain proportion, and calculate the volume flow. Vortex street flowmeter applied to measuring liquid, gas or steam. It has no moving parts, and no dirt problem. Vortex street flowmeter can produce noise, but also for fluid with high velocity, to produce vortex.
Edit by FTD Automation Instruments(www.ftdinstruments.com)