I have to build a digital peak flow meter. I ve read that you can measure the volume metric flow rate using a differential pressure sensor. H ow do i go about doing so. The peak flow meter will be used to measure asthma.
1st work out how the pressure sensor works.
This should let you know the relationship between what it says and the flow rate - which will also depend on the geometry of the device.
Do you know the relationship between fluid pressure and it's speed?
If you know the gauge-pressure at a position in some flow, that can be useful for telling you the speed of the flow... provided you know the relationship between pressure and air speed. You usually also need other information like the geometry of whatever the air is flowing through.
Do you know how pressure relates to air speed?
Do you know how air-speed relates to volume flow?