Bourdon tubes are widely used in pressure measurement devices such as pressure gauges and pressure transducers. These tubes are named after Eugène Bourdon, who invented them in the 19th century. While the basic principle of Bourdon tubes remains the same, there are several variations in their design to suit different pressure measurement applications. Here are some common types of Bourdon tubes:

1. C-Type Bourdon Tube:

   • This is the most common type of Bourdon tube, characterized by its C-shaped cross-section.
   • It is suitable for measuring gauge pressure (pressure relative to atmospheric pressure) and is widely used in pressure gauges for industrial applications.

2. S-Type Bourdon Tube:

   • S-type Bourdon tubes have a helical or spiral shape, resembling the letter "S".
   • They are used in pressure gauges and transducers where space constraints or specific mounting orientations require a compact design.

3. Coiled Bourdon Tube:

   • Coiled Bourdon tubes consist of multiple coils wound concentrically to form the sensing element.
   • They offer higher sensitivity and can measure smaller pressure differentials compared to straight Bourdon tubes.
   • Coiled Bourdon tubes are used in precision pressure gauges and instruments requiring high accuracy and sensitivity.

4. Spiral Bourdon Tube:

   • Spiral Bourdon tubes are similar to S-type tubes but have a single, continuous spiral shape.
   • They provide increased sensitivity and linear response over a wider pressure range compared to C-type tubes.
   • Spiral Bourdon tubes are commonly used in pressure gauges and transducers for applications requiring high accuracy and dynamic response.

5. Helical Bourdon Tube:

   • Helical Bourdon tubes have a helix-shaped design with a spiral coil along the length of the tube.
   • They offer improved linearity, reduced hysteresis, and better shock resistance compared to straight Bourdon tubes.
   • Helical Bourdon tubes are used in high-performance pressure gauges and transducers for critical applications such as aerospace and automotive industries.

6. Twisted Bourdon Tube:

   • Twisted Bourdon tubes have a twisted or irregular shape, allowing for more complex sensing geometries.
   • They are used in specialized pressure measurement applications where customized sensing elements are required to accommodate specific pressure ranges, fluid properties, or environmental conditions.

These are some common types of Bourdon tubes used in pressure measurement devices. The selection of the appropriate Bourdon tube depends on factors such as the pressure range, accuracy requirements, space constraints, and environmental conditions of the application.