Calculate flow rate using differential pressure
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There is currently an orifice plate differential pressure flow transmitter in use. The transmitter’s range is 0–40 kPa, while the process range is 0–330 m3/h. What is the flow rate when the transmitter indicates 30%? (How to calculate the flow rate)
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Could you help me answer this? Thank you!
The flow rate of a orifice plate flow meter is proportional to the square root of the differential pressure; therefore, it depends on whether the square root operation is performed at the transmitter end or inside the control room (on the integrator or DCS).
F=k*√p – there are two cases: 1. In this case, the transmitter does not have a square root function; 30% of the range corresponds to 12 kPa, so k=330÷√40, and F=√12*k, which gives a value of 180.75. 2. When a square root function is available, the calculation is straightforward: 12*330÷40=99. I haven’t calculated it in a long time, so it should be fine