Q. What are the limitation of piezometer?

Answer

Gauge pressure is determined by observing the height to which a column of liquid rises in defiance of gravity. It's a U-shaped tube open at one end to the known ambient pressure and closed at the other to the unknown pressure within the container. Piezometric height is the height of the liquid column as measured by a piezometer. A few of the piezometer's limitations are:Because air would be pulled into the container through the tube vacuum pressure cannot be measured.In order to avoid the necessity for an impractically long vertical tube the pressure being measured should be low.A manometer is a different kind of pressure gauge.