water flowmeters
2006-09-12 01:45:34 · 8 answers · asked by subhash s 1 in Science & Mathematics ➔ Engineering
There are many ways to measure flow. Some are as follows:
Differential pressure.
An orifice is placed in a pipe to create a pressure drop across it. The pressure is measured upstream and downstream by a differential pressure transmitter. The transmitter sends a signal which is proportional to the square root of flow.
Magnetic Flowmeter.
A spool piece placed in the pipeline with no obstructions. There are two small electrodes on the inside of the flowmeter which are in contact with the fluid. An electrical field is energized and measured by the electrodes. Changing electrical field is proportional to flow.
Vortex Flowmeter.
Placed in a pipeline with a single bar running down the middle. As fluid passes the bar it start to create vortices (little whirlpools) on each side of the bar. These vortices alternate and increase in number as the flow increases. They are measured by a slight pressure increase when the occur. The electronics measure the number of vortices which is proportional to flow. If you think of a flag flapping on a flagpole it is easy to imagine.
Coriolis Flowmeter.
The most accurate of all flowmeters it has virtually no moving parts. Flow is routed through two sections of pipe or one pipe with multiple loops with a bend in them. The pipes are slightly electronically vibrated and the vibrations are measured by a second set of electrodes. As flow increases the bend in the pipes cause a torque to occur. The electrodes sense a change in the vibration due to the torque. This is directly linear to flow.
There are other ways to measure flow, but these are the most popular.
2006-09-12 04:36:37 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Depends on what type of flowmeter you are using. They have paddle flowmeters that have a paddle in the flow and turns with water flow. There are oriface flow meters that work on the principles around pressure drop across the oriface. There are some that work based on dopler radar.
2006-09-12 02:56:25 · answer #2 · answered by Jeffrey S 6 · 0⤊ 0⤋
Principals of which flow meter? There are so many of them.
In general you can state flow is the differential is pressure created by a restriction in the path of flow. Take the basic flow element - The Orifice plate
Flow is a derived parameter, which can be found if the operating pressure, temperature and the pressure differential is known.
Flow F is proportional to the (sq.root of DP)*P/T
DP = Differential Pressure
P = Pressure
T=Temperature
I hope you vote me the best answer.
2006-09-12 02:56:45 · answer #3 · answered by cooldude 3 · 0⤊ 0⤋
I say yes to all the intelligent answers above except the most widely used flow meter for water is the Vee shaped weir.
The flow is proportional to the height of the water in the Vee.
This height is usually measured with a "bubbler" instrument.
2006-09-13 11:04:54 · answer #4 · answered by cycloneweaver.com 3 · 0⤊ 0⤋
In addition to the above stated is the "hot wire" type. The velocity of a fluid is determined by the temperature drop (delta T) of a hot wire that is heated with a known Wattage.
Q=A h(velocity) dT
h(velocity)=Q/(A dT)
2006-09-12 09:54:27 · answer #5 · answered by BRUZER 4 · 0⤊ 0⤋
They are typically used to measure the flow rate of a fluid.
2006-09-12 07:55:56 · answer #6 · answered by Anonymous · 0⤊ 0⤋
You first have to differentiate between open channel and pressurized flow.
2006-09-14 12:58:07 · answer #7 · answered by daedgewood 4 · 0⤊ 0⤋
It is usually viscousity.
it actually varies from various types of meters.
2006-09-12 01:50:05 · answer #8 · answered by ? 3 · 0⤊ 0⤋