Diaphragm pressure gauge consists of a metallic tube. This is used for actuating the indicating device. These are often used in gauges to indicate absolute pressure. These are used for the measurement of relatively low pressure up to 1 bar and vacuum. The element is evacuated sealed and mounted within a closed chamber. The pressure to be measured is admitted to the closed chamber and surrounds the diaphragm element. This is a sensitive device well suited for the measurement or detection of small differential pressures applied to each side of diaphragm. The travel of the diaphragm and the stoke available depends on the cross section and the diameter. The gauge is suitable to indicate between 10 psi and 12 psi, but not suitable to indicate between 100 psi and 102 psi