We offer a wide range of fluid machines & in each machine, a wide bore glass tube is mounted vertically in front of a scale graduated 0 to 60cm. At the top close end of every tube, there is zero corresponds. To confined the air inside the tube, a coloured oil is used contained in the metal pressure chamber. This metal pressure chamber is fitted with a Burdon Type gauge calibrated in 0 to 50 lbs. In² & 3.5 Kg/cm² actual pressure. To the air inlet tube, a valve is attached from the pump. According the the increasing pressure of the oil chamber, oil in its actual pressure is directly indicated.