Differential u-tube PA+ pigh1-p2gh2-P3gh3 h2 aPb= P2gh2 t p3gh3-pghI (1) Inclined manometer Pipes a b contain gas PA-P2gl2 sin 0=pb PA-Pb= l sin eDifferential U-tube PA + 1 g h1 - 2gh2 - 3gh3 = PB PA – PB = 2gh2 + 3gh3 -  g h1 Inclined Manometer Pipes A & B contain gas PA - 2 g l2 Sin  = PB PA – PB = 2 g l2 Sin 