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?
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.
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.
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.
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.