7. Signal processing and measurement dynamics (rangeability)

It is undoubtedly one of the weak points of the flowmeter with depressurizing device that its raw signal is proportional, not to the flow rate it measures, but to its square root. This greatly reduces its measuring range, especially since, at least in the current state of the art, the current value of the signal delivered by a differential pressure transducer is subject to a fixed uncertainty in absolute value, equal to a certain percentage of the set end-of-scale value. As an example, this means that the uncertainty of a differential pressure measurement that would only be 0.5% at the end of the scale would be increased to 5% at 1/10 of this maximum value, whereas the flow variation that caused this deviation is only a factor of $\sqrt{10}\cong 3$...