What does manometer mean in practice?
Pressure is read at a specific flow state because the static value can be much higher than the dynamic value.
When does it matter?
One pressure gauge will not show the drop on the filter; you need a measurement before and after the element or a differential pressure gauge.
Which solutions are related to it?
The range is selected so that normal operation does not fall at the extreme end of the scale, and the reading is periodically compared with a control device.