Piezometer tube Open A gauge g hy (1) Simple u-manometer Open A+ pigh =pgh A gauge-p2g h2-P1gh1 x(1) h2 (2) (3)Piezometer Tube PA.gauge =  g h1 Simple U-Manometer P2 = P3 PA + 1gh1 = 2 g h2 PA,gauge = 2 g h2 - 1gh1