I am using SDP32 sensor and got the differential pressure value of the air. I want to convert this value to flow rate. What is the equation for that?

  • $\begingroup$ What type of conduit is it attached to ? $\endgroup$ Oct 11, 2023 at 12:44
  • $\begingroup$ Is that through a calibrated orifice? $\endgroup$
    – Solar Mike
    Oct 11, 2023 at 12:57
  • $\begingroup$ come back, diagram out your system, and describe what your sensor is attached to. $\endgroup$
    – Tiger Guy
    Oct 12, 2023 at 4:20
  • $\begingroup$ If you have enough pressure sensors, you can measure dynamic pressures at different points, giving you an idea of the distribution of flow velocities. If you have static pressures as well as temperatures a good way to obtain density and other fluid properties, and an idea of your geometry, getting flow rates is not unheard of. You need more data than a single differential pressure, which is really just a good way to measure (total pressure - static pressure)=dynamic pressure. $\endgroup$
    – Abel
    Oct 12, 2023 at 10:05

1 Answer 1


In general case pressure difference is described by Hagen–Poiseuille equation. In the case of pipe it can be described by more practical Darcy–Weisbach equation. Simplest way, as i think, is to graduate your sensor by industrial flow meter.


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