Bourdon tube pressure gauges are the most frequently used mechanical pressure measuring instruments. Their pressure element is often referred to as a Bourdon tube: The French engineer Eug�ne Bourdon made use of this functional principle in the center of the 19th century. It is predicated on an elastic spring, a c-shaped, bent tube having an oval cross-section.
The result of pressure on a Bourdon tube
When 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 technique increase the radius of the c-shaped tube. Because of this, the end of the tube moves by around two or three millimetres. This deflection is really a way of measuring the pressure. pressure gauge 10 bar is used in a movement, which turns the linear deflection 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 employed. With เพรสเชอร์เกจ to the geometry, material and material thickness, pressures up to 7,000 bar can be realised. According to the requirement, the pressure elements are constructed with copper alloys, stainless steels or special materials such as for example Monel.
Note
More info on Bourdon tube pressure gauges are available on the WIKA website.