measuring principle of variable area flowmeter
The basic structure of flowmeter includes a vertical taper tube with scale upward and a floater that moves up and down
freely. When the fluid goes through the taper tube bottom-up, it’s throttled by the floater.Differential pressure
between upstream and downstream occurs. If raising force overweighs weight, the floater goes up.Along with floater
rising, the space between floater and taper tube becomes bigger so as to decrease the rising force.When rising force
and weight reach into balance, it is achieving equilibrium of forces. At that time, the floater stays
at a certain height which stands for the flow value of flow meter.