Bourdon tube pressure gauges utilize the elastic sensitive element of a tube to measure pressure through bending or torsional deformation; they are also known as Bourdon tube pressure gauges. One end of the Bourdon tube is fixed, while the other end is movable; its cross-sectional shape is elliptical or flat. Under the action of internal pressure, the non-circular tube gradually expands into a circular shape, causing the movable end to displace in a manner proportional to the pressure. The movable end then moves a pointer to indicate the pressure.
The most commonly used Bourdon tube is the C-type, but there are also spiral, C-type combination, and twisted types. Bourdon tubes are made of copper-based or iron-based alloys. Compared to other pressure-sensitive elements, it has lower sensitivity and is often used to measure larger pressures, frequently in combination with other elastic elements. E. Bourdon obtained a patent for the Bourdon tube in 1852. To this day, the Bourdon tube is still widely used in many instruments, especially for pressure and force measurement.
