Differential pressure transmitter calculation
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(Square of current volumetric flow rate/volumetric flow rate range) = Current differential pressure/range = (Current current - 4) / (20 - 4)? (Square of current mass flow rate/mass flow rate range) = current differential pressure/range = (current current - 4) / (20 - 4)? So, (current volumetric flow rate/volumetric flow rate range) squared = (current mass flow rate/mass flow rate range) squared? ! This isn’t right; I’m confused. How should I solve this problem? The maximum differential pressure of a transmitter is 40 KPA. If the maximum flow rate of the secondary meter is 20 T/H, fill in the table based on the principles of transmitters: Differential Pressure (PA), Differential Current (MA), Flow Current (MA), Flow Rate (T/H). 400, 4.16, ?, 2; 1600, ?, 7.2, ?; 5.44, ?, 6
Have I misunderstood?:
Differential pressure PA, Differential current MA, Flow current MA, Flow rate T/H: 400, 4.16, 5.6, 2; 1600, 4.64, 7.2, 4; 3600, 5.44, 8.8, 6
With simple differential pressure and differential pressure current ratios, the flow rate current and flow rate ratio can be obtained.
Your answer is correct. It’s just that I misunderstood it: when the transmitter does not apply a square root operation, there is a linear relationship between current and differential pressure, and neither of these is related to flow rate. When the transmitter does apply a square root operation, there is a quadratic relationship between current and flow rate, as well as between differential pressure and flow rate; meanwhile, there is a linear relationship between current and differential pressure. Is this correct?
So, (current volumetric flow rate/volumetric flow rate range) squared = (current mass flow rate/mass flow rate range) squared? We generally assume that the density is a constant by default, so there’s no mistake.