Orifice flow meter to integrator
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Why isn’t the relationship between the differential pressure transmitter of the orifice plate flow meter and the accumulator linear? When 4 milliamps are applied, the accumulator displays 0; when 20 milliamps are applied, it displays 3000. The actual full-scale value is indeed 3000. However, at 8 milliamps it shows 1500 instead of 750, at 12 milliamps it shows 2100, and at 16 milliamps it shows 2600. What’s going on? (The input mode selected for the accumulator is differential pressure with non-linear scaling.)
The relationship between the differential pressure transmitter of the orifice plate flow meter and the integrator is not linear
The output of the differential pressure transmitter of the orifice plate flow meter to the integrator follows a square root relationship rather than a linear one.
The relationship between differential pressure and flow rate for orifice plates is square-root related; therefore, the square root operation should be performed either on the transmitter or on the integrator. In your case, the square root function is being applied to the meter, which is why the 4-20mA signal input does not correspond linearly to the displayed value.
ΔP whatever, I don’t know either. Experts, please help!
ΔP whatever, I don’t know either. Experts, please help!
The input method selected for the integrator is differential pressure with nonlinear processing; squaring is the default setting, and this is correct for the 4th floor
For the calculation, there is an option to select the type of input signal; choose options such as “square root of flow rate” or “square root of differential pressure”, and do not select linear!
For the calculation, there is an option to select the type of input signal; choose options such as “square root of flow rate” or “square root of differential pressure”, and do not select linear!