Bellows have a wide range of applications. They can be used as measuring elements, converting pressure into displacement or force. They can also be used as insulating materials, separating two different materials for protection. Furthermore, they can be used as compensating elements to compensate for temperature errors, or for connecting two components.
Bellows have thin walls and high sensitivity, with a measurement range from tens of Pascals to tens of megapascals. Their open end is fixed, while the sealed end is free, utilizing an auxiliary helical spring or leaf spring for added elasticity.
During operation, under internal pressure, the bellows elongates along its length, causing the movable end to displace in a manner proportional to the pressure. The movable end drives a pointer to directly indicate the pressure magnitude. Bellows are often combined with displacement sensors to form pressure sensors that output electrical signals; they are also sometimes used as insulating elements.
