Inclined Manometer

Common problems when measuring pressure differences in low velocity systems as air ventilation system are the low column heights and satisfying accurately. The pressure difference in a inclined u-tube can be expressed as:

pd = h sin() (2), where

h = length, difference in position of the liquid column along the tube (mm, ft)

= angle of column relative the horizontal plane

Inclining the tube manometer will increase the accuracy of the measurement.