Bellows Pressure Sensors Principle


A bellows sensor is an axially flexible, cylindrical enclosure with folded sides. When pressure is applied through an opening, the closed end extends axially as shown in figure.

The movement rotates a pointer by a mechanical linkage. Movement of the bellows is opposed by the spring action of the bellows material, the pressure surrounding the bellows, and usually, the force of an external spring or another bellows.