Water flow rate???

[ruzfactor]

I'm a student of mechanical engineering and I'm working on a project where I need few water flow rate measuring devices. But those are expensive. I was wondering If it is possible to make a digital water flow rate meter?

Any ideas or links needed.

Thanks

 

[KMoffett]

Flow in a pipe?...in a river? What flow rates?...µL/Hr?...cubic meters/sec?



Ken

 

[BrownOut]

We had this discussion not long ago. Can't find the thread. Well, I could if I looked really, really hard

 

[jbeng]

You can get some ideas here: Flow measurement - Wikipedia, the free encyclopedia

 

[dougy83]

A dodgey suggestion: place a sprung vein in the flow path; as the flow increases, the vein rotates. To measure rotation, place a magnet at the pivot coupled to a hall-effect sensor - the voltage out should be proportional to the cosine of the angle. Obviously it will need calibration.

There's a discussion on some flow control here as well http://www.electro-tech-online.com/threads/sprinkler-flow-sensor-help.94178/

 

[ruzfactor]

I wanna measure flow rate inside a 1/2" dia pipe and it should be in cubic meters/sec.

 

[Chippie]

What accuracy do you need?

A cubic metre per second is quite a lot of water....

 

[user_88]

Can you provide additional information regarding the application?
Maybe a little more problem description would evoke some more ideas.

 

[Mr RB]

What accuracy do you need?

A cubic metre per second is quite a lot of water....

You'd be lucky to get a litre a second through a half inch pipe... A cubic meter is 1000 times that.

To ruzfactor, just get some automotive flow rate sensors from the car breakers, they are used on all fuel injected cars.

 

[BrownOut]

the car breakers

Is that like a junkyard?

 

[smanches]

Vacuum sensor on a smaller diameter pipe? If it's an open system, you could just put the pressure sensor on it; no need to venturi it. You'll have to venturi it on a closed system.

 

[tytower]

How do petrol pumps measure flow ?
The old style butterfly spinner didn't measure anything just told you it was flowing.
Perhaps a piston pump driving the flow but the above question seems to be already flowing.

 

[Mr RB]

Brownout; yep, breakers = wreckers = junkyard

tytower; It's not the pump that measures flow, most fuel injected cars have an impeller device that measures fuel flow, they are usually stanless shaft with solvent proof plastic impeller with a tiny inbuilt magnet and an external hall magnetic sensor. They are handy for measuring almost any fluid.

It may be too small for this job but it was a valid suggestion for measuring fluid flow when there were not too many other suggestions.

 

[ruzfactor]

Thnx. I'll try to get one.

 

[Chippie]

It may be too small for this job but it was a valid suggestion for measuring fluid flow when there were not too many other suggestions.

It doesnt measure the flow..it provides a signal to the ecu that calculates the flow...

I'd have suggested a coriolis meter, but then would have received a barrage of questions..err....Whats a coriolis meter?

Did I mention turbine meter?

I think I asked what accuracy was needed but didnt see a response..

Ah well I tried to help..

 

[Mr RB]

It doesnt measure the flow..it provides a signal to the ecu that calculates the flow...
...

???. It measures the flow by providing pulses that increase in frequency as the flow increases.

Or are you saying the "freq output is not perfectly linear to the flow rate" as that is a different thing to "doesn't measure the flow".