Bourdon tube pressure gauge ? operating principle

Bourdon tube pressure gauges will be the most regularly used mechanical pressure measuring instruments. Their pressure element is often known as a Bourdon tube: The French engineer Eug�ne Bourdon made use of this functional principle in the middle of the 19th century. It is based on an elastic spring, a c-shaped, bent tube having an oval cross-section.
The result of pressure on a Bourdon tube
Once the internal space of the Bourdon tube is pressurised, the cross-section is thus altered towards a circular shape. The hoop stresses which are created in this process increase the radius of the c-shaped tube. Subsequently, the finish of the tube moves by around two or three millimetres. This deflection is a measure of the pressure. Slaughter is transferred to a movement, which turns the linear deflection right into a rotary movement and, with a pointer, makes this visible on a scale.
Bourdon tube variants
With the c-shaped bent Bourdon tubes, pressures around 60 bar can be displayed. For higher pressures, helical or spiral-type Bourdon tubes are used. Depending on the geometry, material and material thickness, pressures around 7,000 bar could be realised. Depending on the requirement, the pressure elements are constructed of copper alloys, stainless steels or special materials such as Monel.
Note
Further information on Bourdon tube pressure gauges are available on the WIKA website.

Leave a Comment